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LU-8840 osp: handle EA cache properly
[fs/lustre-release.git] / lustre / lfsck / lfsck_namespace.c
index 7ec48ee..1cb3963 100644 (file)
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2012, 2013, Intel Corporation.
+ * Copyright (c) 2013, 2016, Intel Corporation.
  */
 /*
  * lustre/lfsck/lfsck_namespace.c
 
 #include "lfsck_internal.h"
 
-#define LFSCK_NAMESPACE_MAGIC  0xA0629D03
+#define LFSCK_NAMESPACE_MAGIC_V1       0xA0629D03
+#define LFSCK_NAMESPACE_MAGIC_V2       0xA0621A0B
+
+/* For Lustre-2.x (x <= 6), the namespace LFSCK used LFSCK_NAMESPACE_MAGIC_V1
+ * as the trace file magic. When downgrade to such old release, the old LFSCK
+ * will not recognize the new LFSCK_NAMESPACE_MAGIC_V2 in the new trace file,
+ * then it will reset the whole LFSCK, and will not cause start failure. The
+ * similar case will happen when upgrade from such old release. */
+#define LFSCK_NAMESPACE_MAGIC          LFSCK_NAMESPACE_MAGIC_V2
 
 enum lfsck_nameentry_check {
        LFSCK_NAMEENTRY_DEAD            = 1, /* The object has been unlinked. */
@@ -49,10 +57,9 @@ enum lfsck_nameentry_check {
        LFSCK_NAMEENTRY_RECREATED       = 3, /* The entry has been recreated. */
 };
 
-static const char lfsck_namespace_name[] = "lfsck_namespace";
-
 static struct lfsck_namespace_req *
 lfsck_namespace_assistant_req_init(struct lfsck_instance *lfsck,
+                                  struct lfsck_assistant_object *lso,
                                   struct lu_dirent *ent, __u16 type)
 {
        struct lfsck_namespace_req *lnr;
@@ -64,10 +71,9 @@ lfsck_namespace_assistant_req_init(struct lfsck_instance *lfsck,
                return ERR_PTR(-ENOMEM);
 
        INIT_LIST_HEAD(&lnr->lnr_lar.lar_list);
-       lu_object_get(&lfsck->li_obj_dir->do_lu);
-       lnr->lnr_obj = lfsck->li_obj_dir;
+       lnr->lnr_lar.lar_parent = lfsck_assistant_object_get(lso);
+       lnr->lnr_lmv = lfsck_lmv_get(lfsck->li_lmv);
        lnr->lnr_fid = ent->lde_fid;
-       lnr->lnr_oit_cookie = lfsck->li_pos_current.lp_oit_cookie;
        lnr->lnr_dir_cookie = ent->lde_hash;
        lnr->lnr_attr = ent->lde_attrs;
        lnr->lnr_size = size;
@@ -84,7 +90,10 @@ static void lfsck_namespace_assistant_req_fini(const struct lu_env *env,
        struct lfsck_namespace_req *lnr =
                        container_of0(lar, struct lfsck_namespace_req, lnr_lar);
 
-       lu_object_put(env, &lnr->lnr_obj->do_lu);
+       if (lnr->lnr_lmv != NULL)
+               lfsck_lmv_put(env, lnr->lnr_lmv);
+
+       lfsck_assistant_object_put(env, lar->lar_parent);
        OBD_FREE(lnr, lnr->lnr_size);
 }
 
@@ -131,6 +140,33 @@ static void lfsck_namespace_le_to_cpu(struct lfsck_namespace *dst,
        dst->ln_bad_type_repaired = le64_to_cpu(src->ln_bad_type_repaired);
        dst->ln_lost_dirent_repaired =
                                le64_to_cpu(src->ln_lost_dirent_repaired);
+       dst->ln_striped_dirs_scanned =
+                               le64_to_cpu(src->ln_striped_dirs_scanned);
+       dst->ln_striped_dirs_repaired =
+                               le64_to_cpu(src->ln_striped_dirs_repaired);
+       dst->ln_striped_dirs_failed =
+                               le64_to_cpu(src->ln_striped_dirs_failed);
+       dst->ln_striped_dirs_disabled =
+                               le64_to_cpu(src->ln_striped_dirs_disabled);
+       dst->ln_striped_dirs_skipped =
+                               le64_to_cpu(src->ln_striped_dirs_skipped);
+       dst->ln_striped_shards_scanned =
+                               le64_to_cpu(src->ln_striped_shards_scanned);
+       dst->ln_striped_shards_repaired =
+                               le64_to_cpu(src->ln_striped_shards_repaired);
+       dst->ln_striped_shards_failed =
+                               le64_to_cpu(src->ln_striped_shards_failed);
+       dst->ln_striped_shards_skipped =
+                               le64_to_cpu(src->ln_striped_shards_skipped);
+       dst->ln_name_hash_repaired = le64_to_cpu(src->ln_name_hash_repaired);
+       dst->ln_local_lpf_scanned = le64_to_cpu(src->ln_local_lpf_scanned);
+       dst->ln_local_lpf_moved = le64_to_cpu(src->ln_local_lpf_moved);
+       dst->ln_local_lpf_skipped = le64_to_cpu(src->ln_local_lpf_skipped);
+       dst->ln_local_lpf_failed = le64_to_cpu(src->ln_local_lpf_failed);
+       dst->ln_bitmap_size = le32_to_cpu(src->ln_bitmap_size);
+       dst->ln_time_latest_reset = le32_to_cpu(src->ln_time_latest_reset);
+       dst->ln_linkea_overflow_cleared =
+                               le64_to_cpu(src->ln_linkea_overflow_cleared);
 }
 
 static void lfsck_namespace_cpu_to_le(struct lfsck_namespace *dst,
@@ -176,6 +212,33 @@ static void lfsck_namespace_cpu_to_le(struct lfsck_namespace *dst,
        dst->ln_bad_type_repaired = cpu_to_le64(src->ln_bad_type_repaired);
        dst->ln_lost_dirent_repaired =
                                cpu_to_le64(src->ln_lost_dirent_repaired);
+       dst->ln_striped_dirs_scanned =
+                               cpu_to_le64(src->ln_striped_dirs_scanned);
+       dst->ln_striped_dirs_repaired =
+                               cpu_to_le64(src->ln_striped_dirs_repaired);
+       dst->ln_striped_dirs_failed =
+                               cpu_to_le64(src->ln_striped_dirs_failed);
+       dst->ln_striped_dirs_disabled =
+                               cpu_to_le64(src->ln_striped_dirs_disabled);
+       dst->ln_striped_dirs_skipped =
+                               cpu_to_le64(src->ln_striped_dirs_skipped);
+       dst->ln_striped_shards_scanned =
+                               cpu_to_le64(src->ln_striped_shards_scanned);
+       dst->ln_striped_shards_repaired =
+                               cpu_to_le64(src->ln_striped_shards_repaired);
+       dst->ln_striped_shards_failed =
+                               cpu_to_le64(src->ln_striped_shards_failed);
+       dst->ln_striped_shards_skipped =
+                               cpu_to_le64(src->ln_striped_shards_skipped);
+       dst->ln_name_hash_repaired = cpu_to_le64(src->ln_name_hash_repaired);
+       dst->ln_local_lpf_scanned = cpu_to_le64(src->ln_local_lpf_scanned);
+       dst->ln_local_lpf_moved = cpu_to_le64(src->ln_local_lpf_moved);
+       dst->ln_local_lpf_skipped = cpu_to_le64(src->ln_local_lpf_skipped);
+       dst->ln_local_lpf_failed = cpu_to_le64(src->ln_local_lpf_failed);
+       dst->ln_bitmap_size = cpu_to_le32(src->ln_bitmap_size);
+       dst->ln_time_latest_reset = cpu_to_le32(src->ln_time_latest_reset);
+       dst->ln_linkea_overflow_cleared =
+                               cpu_to_le64(src->ln_linkea_overflow_cleared);
 }
 
 static void lfsck_namespace_record_failure(const struct lu_env *env,
@@ -191,7 +254,7 @@ static void lfsck_namespace_record_failure(const struct lu_env *env,
                ns->ln_pos_first_inconsistent = pos;
 
                CDEBUG(D_LFSCK, "%s: namespace LFSCK hit first non-repaired "
-                      "inconsistency at the pos ["LPU64", "DFID", "LPX64"]\n",
+                      "inconsistency at the pos [%llu, "DFID", %#llx]\n",
                       lfsck_lfsck2name(lfsck),
                       ns->ln_pos_first_inconsistent.lp_oit_cookie,
                       PFID(&ns->ln_pos_first_inconsistent.lp_dir_parent),
@@ -200,9 +263,81 @@ static void lfsck_namespace_record_failure(const struct lu_env *env,
 }
 
 /**
- * \retval +ve: the lfsck_namespace is broken, the caller should reset it.
- * \retval 0: succeed.
- * \retval -ve: failed cases.
+ * Load the MDT bitmap from the lfsck_namespace trace file.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ *
+ * \retval             0 for success
+ * \retval             negative error number on failure or data corruption
+ */
+static int lfsck_namespace_load_bitmap(const struct lu_env *env,
+                                      struct lfsck_component *com)
+{
+       struct dt_object                *obj    = com->lc_obj;
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct cfs_bitmap                       *bitmap = lad->lad_bitmap;
+       ssize_t                          size;
+       __u32                            nbits;
+       int                              rc;
+       ENTRY;
+
+       if (com->lc_lfsck->li_mdt_descs.ltd_tgts_bitmap->size >
+           ns->ln_bitmap_size)
+               nbits = com->lc_lfsck->li_mdt_descs.ltd_tgts_bitmap->size;
+       else
+               nbits = ns->ln_bitmap_size;
+
+       if (unlikely(nbits < BITS_PER_LONG))
+               nbits = BITS_PER_LONG;
+
+       if (nbits > bitmap->size) {
+               __u32 new_bits = bitmap->size;
+               struct cfs_bitmap *new_bitmap;
+
+               while (new_bits < nbits)
+                       new_bits <<= 1;
+
+               new_bitmap = CFS_ALLOCATE_BITMAP(new_bits);
+               if (new_bitmap == NULL)
+                       RETURN(-ENOMEM);
+
+               lad->lad_bitmap = new_bitmap;
+               CFS_FREE_BITMAP(bitmap);
+               bitmap = new_bitmap;
+       }
+
+       if (ns->ln_bitmap_size == 0) {
+               lad->lad_incomplete = 0;
+               CFS_RESET_BITMAP(bitmap);
+
+               RETURN(0);
+       }
+
+       size = (ns->ln_bitmap_size + 7) >> 3;
+       rc = dt_xattr_get(env, obj,
+                         lfsck_buf_get(env, bitmap->data, size),
+                         XATTR_NAME_LFSCK_BITMAP);
+       if (rc != size)
+               RETURN(rc >= 0 ? -EINVAL : rc);
+
+       if (cfs_bitmap_check_empty(bitmap))
+               lad->lad_incomplete = 0;
+       else
+               lad->lad_incomplete = 1;
+
+       RETURN(0);
+}
+
+/**
+ * Load namespace LFSCK statistics information from the trace file.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ *
+ * \retval             0 for success
+ * \retval             negative error number on failure
  */
 static int lfsck_namespace_load(const struct lu_env *env,
                                struct lfsck_component *com)
@@ -212,7 +347,7 @@ static int lfsck_namespace_load(const struct lu_env *env,
 
        rc = dt_xattr_get(env, com->lc_obj,
                          lfsck_buf_get(env, com->lc_file_disk, len),
-                         XATTR_NAME_LFSCK_NAMESPACE, BYPASS_CAPA);
+                         XATTR_NAME_LFSCK_NAMESPACE);
        if (rc == len) {
                struct lfsck_namespace *ns = com->lc_file_ram;
 
@@ -222,7 +357,7 @@ static int lfsck_namespace_load(const struct lu_env *env,
                        CDEBUG(D_LFSCK, "%s: invalid lfsck_namespace magic "
                               "%#x != %#x\n", lfsck_lfsck2name(com->lc_lfsck),
                               ns->ln_magic, LFSCK_NAMESPACE_MAGIC);
-                       rc = 1;
+                       rc = -ESTALE;
                } else {
                        rc = 0;
                }
@@ -231,24 +366,39 @@ static int lfsck_namespace_load(const struct lu_env *env,
                       "expected = %d: rc = %d\n",
                       lfsck_lfsck2name(com->lc_lfsck), len, rc);
                if (rc >= 0)
-                       rc = 1;
+                       rc = -ESTALE;
        }
+
        return rc;
 }
 
 static int lfsck_namespace_store(const struct lu_env *env,
-                                struct lfsck_component *com, bool init)
+                                struct lfsck_component *com)
 {
-       struct dt_object        *obj    = com->lc_obj;
-       struct lfsck_instance   *lfsck  = com->lc_lfsck;
-       struct thandle          *handle;
-       int                      len    = com->lc_file_size;
-       int                      rc;
+       struct dt_object                *obj    = com->lc_obj;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct dt_device                *dev    = lfsck_obj2dev(obj);
+       struct cfs_bitmap               *bitmap = NULL;
+       struct thandle                  *handle;
+       __u32                            nbits  = 0;
+       int                              len    = com->lc_file_size;
+       int                              rc;
        ENTRY;
 
+       if (lad != NULL) {
+               bitmap = lad->lad_bitmap;
+               nbits = bitmap->size;
+
+               LASSERT(nbits > 0);
+               LASSERTF((nbits & 7) == 0, "Invalid nbits %u\n", nbits);
+       }
+
+       ns->ln_bitmap_size = nbits;
        lfsck_namespace_cpu_to_le((struct lfsck_namespace *)com->lc_file_disk,
-                                 (struct lfsck_namespace *)com->lc_file_ram);
-       handle = dt_trans_create(env, lfsck->li_bottom);
+                                 ns);
+       handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
                GOTO(log, rc = PTR_ERR(handle));
 
@@ -258,20 +408,30 @@ static int lfsck_namespace_store(const struct lu_env *env,
        if (rc != 0)
                GOTO(out, rc);
 
-       rc = dt_trans_start_local(env, lfsck->li_bottom, handle);
+       if (bitmap != NULL) {
+               rc = dt_declare_xattr_set(env, obj,
+                               lfsck_buf_get(env, bitmap->data, nbits >> 3),
+                               XATTR_NAME_LFSCK_BITMAP, 0, handle);
+               if (rc != 0)
+                       GOTO(out, rc);
+       }
+
+       rc = dt_trans_start_local(env, dev, handle);
        if (rc != 0)
                GOTO(out, rc);
 
        rc = dt_xattr_set(env, obj,
                          lfsck_buf_get(env, com->lc_file_disk, len),
-                         XATTR_NAME_LFSCK_NAMESPACE,
-                         init ? LU_XATTR_CREATE : LU_XATTR_REPLACE,
-                         handle, BYPASS_CAPA);
+                         XATTR_NAME_LFSCK_NAMESPACE, 0, handle);
+       if (rc == 0 && bitmap != NULL)
+               rc = dt_xattr_set(env, obj,
+                                 lfsck_buf_get(env, bitmap->data, nbits >> 3),
+                                 XATTR_NAME_LFSCK_BITMAP, 0, handle);
 
        GOTO(out, rc);
 
 out:
-       dt_trans_stop(env, lfsck->li_bottom, handle);
+       dt_trans_stop(env, dev, handle);
 
 log:
        if (rc != 0)
@@ -289,22 +449,27 @@ static int lfsck_namespace_init(const struct lu_env *env,
        memset(ns, 0, sizeof(*ns));
        ns->ln_magic = LFSCK_NAMESPACE_MAGIC;
        ns->ln_status = LS_INIT;
+       ns->ln_time_latest_reset = cfs_time_current_sec();
        down_write(&com->lc_sem);
-       rc = lfsck_namespace_store(env, com, true);
+       rc = lfsck_namespace_store(env, com);
+       if (rc == 0)
+               rc = lfsck_load_sub_trace_files(env, com,
+                       &dt_lfsck_namespace_features, LFSCK_NAMESPACE, true);
        up_write(&com->lc_sem);
+
        return rc;
 }
 
 /**
- * Update the namespace LFSCK tracing file for the given @fid
+ * Update the namespace LFSCK trace file for the given @fid
  *
  * \param[in] env      pointer to the thread context
  * \param[in] com      pointer to the lfsck component
  * \param[in] fid      the fid which flags to be updated in the lfsck
- *                     tracing file
+ *                     trace file
  * \param[in] add      true if add new flags, otherwise remove flags
  *
- * \retval             0 for succeed or nothing to be done
+ * \retval             0 for success or nothing to be done
  * \retval             negative error number on failure
  */
 int lfsck_namespace_trace_update(const struct lu_env *env,
@@ -313,10 +478,11 @@ int lfsck_namespace_trace_update(const struct lu_env *env,
                                 const __u8 flags, bool add)
 {
        struct lfsck_instance   *lfsck  = com->lc_lfsck;
-       struct dt_object        *obj    = com->lc_obj;
+       struct dt_object        *obj;
        struct lu_fid           *key    = &lfsck_env_info(env)->lti_fid3;
-       struct dt_device        *dev    = lfsck->li_bottom;
+       struct dt_device        *dev;
        struct thandle          *th     = NULL;
+       int                      idx;
        int                      rc     = 0;
        __u8                     old    = 0;
        __u8                     new    = 0;
@@ -324,10 +490,22 @@ int lfsck_namespace_trace_update(const struct lu_env *env,
 
        LASSERT(flags != 0);
 
-       down_write(&com->lc_sem);
+       if (unlikely(!fid_is_sane(fid)))
+               RETURN(0);
+
+       idx = lfsck_sub_trace_file_fid2idx(fid);
+       mutex_lock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+       obj = com->lc_sub_trace_objs[idx].lsto_obj;
+       if (unlikely(obj == NULL)) {
+               mutex_unlock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+               RETURN(0);
+       }
+
+       lfsck_object_get(obj);
+       dev = lfsck_obj2dev(obj);
        fid_cpu_to_be(key, fid);
        rc = dt_lookup(env, obj, (struct dt_rec *)&old,
-                      (const struct dt_key *)key, BYPASS_CAPA);
+                      (const struct dt_key *)key);
        if (rc == -ENOENT) {
                if (!add)
                        GOTO(unlock, rc = 0);
@@ -374,15 +552,14 @@ int lfsck_namespace_trace_update(const struct lu_env *env,
                GOTO(log, rc);
 
        if (old != 0) {
-               rc = dt_delete(env, obj, (const struct dt_key *)key,
-                              th, BYPASS_CAPA);
+               rc = dt_delete(env, obj, (const struct dt_key *)key, th);
                if (rc != 0)
                        GOTO(log, rc);
        }
 
        if (new != 0) {
                rc = dt_insert(env, obj, (const struct dt_rec *)&new,
-                              (const struct dt_key *)key, th, BYPASS_CAPA, 1);
+                              (const struct dt_key *)key, th, 1);
                if (rc != 0)
                        GOTO(log, rc);
        }
@@ -394,19 +571,20 @@ log:
                dt_trans_stop(env, dev, th);
 
        CDEBUG(D_LFSCK, "%s: namespace LFSCK %s flags for "DFID" in the "
-              "tracing file, flags %x, old %x, new %x: rc = %d\n",
+              "trace file, flags %x, old %x, new %x: rc = %d\n",
               lfsck_lfsck2name(lfsck), add ? "add" : "del", PFID(fid),
               (__u32)flags, (__u32)old, (__u32)new, rc);
 
 unlock:
-       up_write(&com->lc_sem);
+       mutex_unlock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+       lfsck_object_put(env, obj);
 
        return rc;
 }
 
-static int lfsck_namespace_check_exist(const struct lu_env *env,
-                                      struct dt_object *dir,
-                                      struct dt_object *obj, const char *name)
+int lfsck_namespace_check_exist(const struct lu_env *env,
+                               struct dt_object *dir,
+                               struct dt_object *obj, const char *name)
 {
        struct lu_fid    *fid = &lfsck_env_info(env)->lti_fid;
        int               rc;
@@ -416,7 +594,7 @@ static int lfsck_namespace_check_exist(const struct lu_env *env,
                RETURN(LFSCK_NAMEENTRY_DEAD);
 
        rc = dt_lookup(env, dir, (struct dt_rec *)fid,
-                      (const struct dt_key *)name, BYPASS_CAPA);
+                      (const struct dt_key *)name);
        if (rc == -ENOENT)
                RETURN(LFSCK_NAMEENTRY_REMOVED);
 
@@ -435,20 +613,23 @@ static int lfsck_declare_namespace_exec_dir(const struct lu_env *env,
 {
        int rc;
 
+       /* For remote updating LINKEA, there may be further LFSCK action
+        * on remote MDT after the updating, so update the LINKEA ASAP. */
+       if (dt_object_remote(obj))
+               handle->th_sync = 1;
+
        /* For destroying all invalid linkEA entries. */
        rc = dt_declare_xattr_del(env, obj, XATTR_NAME_LINK, handle);
-       if (rc != 0)
-               return rc;
-
-       /* For insert new linkEA entry. */
-       rc = dt_declare_xattr_set(env, obj,
-                       lfsck_buf_get_const(env, NULL, DEFAULT_LINKEA_SIZE),
+       if (rc == 0)
+               /* For insert new linkEA entry. */
+               rc = dt_declare_xattr_set(env, obj,
+                       lfsck_buf_get_const(env, NULL, MAX_LINKEA_SIZE),
                        XATTR_NAME_LINK, 0, handle);
        return rc;
 }
 
 int __lfsck_links_read(const struct lu_env *env, struct dt_object *obj,
-                      struct linkea_data *ldata)
+                      struct linkea_data *ldata, bool with_rec)
 {
        int rc;
 
@@ -458,24 +639,32 @@ int __lfsck_links_read(const struct lu_env *env, struct dt_object *obj,
        if (!dt_object_exists(obj))
                return -ENOENT;
 
-       rc = dt_xattr_get(env, obj, ldata->ld_buf, XATTR_NAME_LINK, BYPASS_CAPA);
+       rc = dt_xattr_get(env, obj, ldata->ld_buf, XATTR_NAME_LINK);
        if (rc == -ERANGE) {
                /* Buf was too small, figure out what we need. */
-               rc = dt_xattr_get(env, obj, &LU_BUF_NULL, XATTR_NAME_LINK,
-                                 BYPASS_CAPA);
-               if (rc <= 0)
+               rc = dt_xattr_get(env, obj, &LU_BUF_NULL, XATTR_NAME_LINK);
+               if (unlikely(rc == 0))
+                       return -ENODATA;
+
+               if (rc < 0)
                        return rc;
 
                lu_buf_realloc(ldata->ld_buf, rc);
                if (ldata->ld_buf->lb_buf == NULL)
                        return -ENOMEM;
 
-               rc = dt_xattr_get(env, obj, ldata->ld_buf, XATTR_NAME_LINK,
-                                 BYPASS_CAPA);
+               rc = dt_xattr_get(env, obj, ldata->ld_buf, XATTR_NAME_LINK);
        }
 
-       if (rc > 0)
-               rc = linkea_init(ldata);
+       if (unlikely(rc == 0))
+               return -ENODATA;
+
+       if (rc > 0) {
+               if (with_rec)
+                       rc = linkea_init_with_rec(ldata);
+               else
+                       rc = linkea_init(ldata);
+       }
 
        return rc;
 }
@@ -497,7 +686,7 @@ static int lfsck_namespace_links_remove(const struct lu_env *env,
                                        struct dt_object *obj)
 {
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
-       struct dt_device                *dev    = lfsck->li_bottom;
+       struct dt_device                *dev    = lfsck_obj2dev(obj);
        struct thandle                  *th     = NULL;
        int                              rc     = 0;
        ENTRY;
@@ -523,7 +712,7 @@ static int lfsck_namespace_links_remove(const struct lu_env *env,
        if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
                GOTO(unlock, rc = 0);
 
-       rc = dt_xattr_del(env, obj, XATTR_NAME_LINK, th, BYPASS_CAPA);
+       rc = dt_xattr_del(env, obj, XATTR_NAME_LINK, th);
 
        GOTO(unlock, rc);
 
@@ -550,24 +739,77 @@ log:
 static int lfsck_links_write(const struct lu_env *env, struct dt_object *obj,
                             struct linkea_data *ldata, struct thandle *handle)
 {
-       const struct lu_buf *buf = lfsck_buf_get_const(env,
-                                                      ldata->ld_buf->lb_buf,
-                                                      ldata->ld_leh->leh_len);
+       struct lu_buf buf;
+       int rc;
+
+       lfsck_buf_init(&buf, ldata->ld_buf->lb_buf, ldata->ld_leh->leh_len);
 
-       return dt_xattr_set(env, obj, buf, XATTR_NAME_LINK, 0, handle,
-                           BYPASS_CAPA);
+again:
+       rc = dt_xattr_set(env, obj, &buf, XATTR_NAME_LINK, 0, handle);
+       if (unlikely(rc == -ENOSPC)) {
+               rc = linkea_overflow_shrink(ldata);
+               if (likely(rc > 0)) {
+                       buf.lb_len = rc;
+                       goto again;
+               }
+       }
+
+       return rc;
 }
 
-static void lfsck_namespace_unpack_linkea_entry(struct linkea_data *ldata,
-                                               struct lu_name *cname,
-                                               struct lu_fid *pfid,
-                                               char *buf)
+static int lfsck_namespace_unpack_linkea_entry(struct linkea_data *ldata,
+                                              struct lu_name *cname,
+                                              struct lu_fid *pfid,
+                                              char *buf, const int buflen)
 {
        linkea_entry_unpack(ldata->ld_lee, &ldata->ld_reclen, cname, pfid);
+       if (unlikely(ldata->ld_reclen <= 0 ||
+                    ldata->ld_reclen + sizeof(struct link_ea_header) >
+                       ldata->ld_leh->leh_len ||
+                    cname->ln_namelen <= 0 ||
+                    cname->ln_namelen > NAME_MAX ||
+                    cname->ln_namelen >= buflen ||
+                    !fid_is_sane(pfid)))
+               return -EINVAL;
+
        /* To guarantee the 'name' is terminated with '0'. */
        memcpy(buf, cname->ln_name, cname->ln_namelen);
        buf[cname->ln_namelen] = 0;
        cname->ln_name = buf;
+
+       return 0;
+}
+
+static void lfsck_linkea_del_buf(struct linkea_data *ldata,
+                                const struct lu_name *lname)
+{
+       LASSERT(ldata->ld_leh != NULL && ldata->ld_lee != NULL);
+
+       /* If current record is corrupted, all the subsequent
+        * records will be dropped. */
+       if (unlikely(ldata->ld_reclen <= 0 ||
+                    ldata->ld_reclen + sizeof(struct link_ea_header) >
+                       ldata->ld_leh->leh_len)) {
+               void *ptr = ldata->ld_lee;
+
+               ldata->ld_leh->leh_len = sizeof(struct link_ea_header);
+               ldata->ld_leh->leh_reccount = 0;
+               linkea_first_entry(ldata);
+               while (ldata->ld_lee != NULL &&
+                      (char *)ldata->ld_lee < (char *)ptr) {
+                       int reclen = (ldata->ld_lee->lee_reclen[0] << 8) |
+                                    ldata->ld_lee->lee_reclen[1];
+
+                       ldata->ld_leh->leh_len += reclen;
+                       ldata->ld_leh->leh_reccount++;
+                       ldata->ld_lee = (struct link_ea_entry *)
+                                       ((char *)ldata->ld_lee + reclen);
+               }
+
+               ldata->ld_lee = NULL;
+       } else {
+               linkea_del_buf(ldata, lname);
+       }
 }
 
 static int lfsck_namespace_filter_linkea_entry(struct linkea_data *ldata,
@@ -591,7 +833,7 @@ static int lfsck_namespace_filter_linkea_entry(struct linkea_data *ldata,
                        if (!remove)
                                break;
 
-                       linkea_del_buf(ldata, cname);
+                       lfsck_linkea_del_buf(ldata, cname);
                } else {
                        linkea_next_entry(ldata);
                }
@@ -626,6 +868,8 @@ static int lfsck_namespace_filter_linkea_entry(struct linkea_data *ldata,
  *  type "O":          The MDT-object has no linkEA, and there is no name
  *                     entry that references the MDT-object.
  *
+ *  type "S":          The orphan MDT-object is a shard of a striped directory
+ *
  * \see lfsck_layout_recreate_parent() for more types.
  *
  * The orphan name will be like:
@@ -647,16 +891,17 @@ static int lfsck_namespace_insert_orphan(const struct lu_env *env,
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
        struct lu_name                  *cname  = &info->lti_name;
        struct dt_insert_rec            *rec    = &info->lti_dt_rec;
-       struct lu_fid                   *tfid   = &info->lti_fid5;
+       struct lu_attr                  *la     = &info->lti_la2;
        const struct lu_fid             *cfid   = lfsck_dto2fid(orphan);
        const struct lu_fid             *pfid;
+       struct lu_fid                    tfid;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
-       struct dt_device                *dev    = lfsck->li_bottom;
+       struct dt_device                *dev    = lfsck_obj2dev(orphan);
        struct dt_object                *parent;
        struct thandle                  *th     = NULL;
-       struct lustre_handle             plh    = { 0 };
+       struct lfsck_lock_handle        *pllh   = &info->lti_llh;
        struct lustre_handle             clh    = { 0 };
-       struct linkea_data               ldata  = { 0 };
+       struct linkea_data               ldata2 = { NULL };
        struct lu_buf                    linkea_buf;
        int                              namelen;
        int                              idx    = 0;
@@ -665,53 +910,63 @@ static int lfsck_namespace_insert_orphan(const struct lu_env *env,
        ENTRY;
 
        cname->ln_name = NULL;
-       /* Create .lustre/lost+found/MDTxxxx when needed. */
-       if (unlikely(lfsck->li_lpf_obj == NULL)) {
-               rc = lfsck_create_lpf(env, lfsck);
-               if (rc != 0)
-                       GOTO(log, rc);
-       }
+       if (unlikely(lfsck->li_lpf_obj == NULL))
+               GOTO(log, rc = -ENXIO);
 
        parent = lfsck->li_lpf_obj;
        pfid = lfsck_dto2fid(parent);
 
-       /* Hold update lock on the parent to prevent others to access. */
-       rc = lfsck_ibits_lock(env, lfsck, parent, &plh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
-       if (rc != 0)
-               GOTO(log, rc);
-
+again:
        do {
                namelen = snprintf(info->lti_key, NAME_MAX, DFID"%s-%s-%d",
                                   PFID(cfid), infix, type, idx++);
-               rc = dt_lookup(env, parent, (struct dt_rec *)tfid,
-                              (const struct dt_key *)info->lti_key,
-                              BYPASS_CAPA);
+               rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                              (const struct dt_key *)info->lti_key);
                if (rc != 0 && rc != -ENOENT)
                        GOTO(log, rc);
 
-               if (unlikely(rc == 0 && lu_fid_eq(cfid, tfid)))
+               if (unlikely(rc == 0 && lu_fid_eq(cfid, &tfid)))
                        exist = true;
        } while (rc == 0 && !exist);
 
-       cname->ln_name = info->lti_key;
-       cname->ln_namelen = namelen;
-       rc = linkea_data_new(&ldata, &info->lti_linkea_buf2);
+       rc = lfsck_lock(env, lfsck, parent, info->lti_key, pllh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                GOTO(log, rc);
 
-       rc = linkea_add_buf(&ldata, cname, pfid);
+       /* Re-check whether the name conflict with othrs after taken
+        * the ldlm lock. */
+       rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                      (const struct dt_key *)info->lti_key);
+       if (rc == 0) {
+               if (!lu_fid_eq(cfid, &tfid)) {
+                       exist = false;
+                       lfsck_unlock(pllh);
+                       goto again;
+               }
+
+               exist = true;
+       } else if (rc != -ENOENT) {
+               GOTO(log, rc);
+       } else {
+               exist = false;
+       }
+
+       cname->ln_name = info->lti_key;
+       cname->ln_namelen = namelen;
+       rc = linkea_links_new(&ldata2, &info->lti_linkea_buf2,
+                             cname, pfid);
        if (rc != 0)
                GOTO(log, rc);
 
        rc = lfsck_ibits_lock(env, lfsck, orphan, &clh,
-                             MDS_INODELOCK_UPDATE | MDS_INODELOCK_LOOKUP,
-                             LCK_EX);
+                             MDS_INODELOCK_UPDATE | MDS_INODELOCK_LOOKUP |
+                             MDS_INODELOCK_XATTR, LCK_EX);
        if (rc != 0)
                GOTO(log, rc);
 
-       lfsck_buf_init(&linkea_buf, ldata.ld_buf->lb_buf,
-                      ldata.ld_leh->leh_len);
+       lfsck_buf_init(&linkea_buf, ldata2.ld_buf->lb_buf,
+                      ldata2.ld_leh->leh_len);
        th = dt_trans_create(env, dev);
        if (IS_ERR(th))
                GOTO(log, rc = PTR_ERR(th));
@@ -751,38 +1006,42 @@ static int lfsck_namespace_insert_orphan(const struct lu_env *env,
                }
        }
 
+       memset(la, 0, sizeof(*la));
+       la->la_ctime = cfs_time_current_sec();
+       la->la_valid = LA_CTIME;
+       rc = dt_declare_attr_set(env, orphan, la, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
        rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
        dt_write_lock(env, orphan, 0);
-       rc = lfsck_links_read(env, orphan, &ldata);
-       if (likely((rc == -ENODATA) || (rc == -EINVAL) ||
-                  (rc == 0 && ldata.ld_leh->leh_reccount == 0))) {
+       rc = lfsck_links_read2_with_rec(env, orphan, &ldata2);
+       if (likely(rc == -ENODATA || rc == -EINVAL)) {
                if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
                        GOTO(unlock, rc = 1);
 
                if (S_ISDIR(lfsck_object_type(orphan))) {
                        rc = dt_delete(env, orphan,
-                                      (const struct dt_key *)dotdot, th,
-                                      BYPASS_CAPA);
+                                      (const struct dt_key *)dotdot, th);
                        if (rc != 0)
                                GOTO(unlock, rc);
 
                        rec->rec_type = S_IFDIR;
                        rec->rec_fid = pfid;
                        rc = dt_insert(env, orphan, (const struct dt_rec *)rec,
-                                      (const struct dt_key *)dotdot, th,
-                                      BYPASS_CAPA, 1);
+                                      (const struct dt_key *)dotdot, th, 1);
                        if (rc != 0)
                                GOTO(unlock, rc);
                }
 
                rc = dt_xattr_set(env, orphan, &linkea_buf, XATTR_NAME_LINK, 0,
-                                 th, BYPASS_CAPA);
+                                 th);
        } else {
                if (rc == 0 && count != NULL)
-                       *count = ldata.ld_leh->leh_reccount;
+                       *count = ldata2.ld_leh->leh_reccount;
 
                GOTO(unlock, rc);
        }
@@ -792,8 +1051,7 @@ static int lfsck_namespace_insert_orphan(const struct lu_env *env,
                rec->rec_type = lfsck_object_type(orphan) & S_IFMT;
                rec->rec_fid = cfid;
                rc = dt_insert(env, parent, (const struct dt_rec *)rec,
-                              (const struct dt_key *)cname->ln_name,
-                              th, BYPASS_CAPA, 1);
+                              (const struct dt_key *)cname->ln_name, th, 1);
                if (rc == 0 && S_ISDIR(rec->rec_type)) {
                        dt_write_lock(env, parent, 0);
                        rc = dt_ref_add(env, parent, th);
@@ -801,6 +1059,9 @@ static int lfsck_namespace_insert_orphan(const struct lu_env *env,
                }
        }
 
+       if (rc == 0)
+               rc = dt_attr_set(env, orphan, la, th);
+
        GOTO(stop, rc = (rc == 0 ? 1 : rc));
 
 unlock:
@@ -811,7 +1072,7 @@ stop:
 
 log:
        lfsck_ibits_unlock(&clh, LCK_EX);
-       lfsck_ibits_unlock(&plh, LCK_EX);
+       lfsck_unlock(pllh);
        CDEBUG(D_LFSCK, "%s: namespace LFSCK insert orphan for the "
               "object "DFID", name = %s: rc = %d\n",
               lfsck_lfsck2name(lfsck), PFID(cfid),
@@ -858,21 +1119,34 @@ static int lfsck_namespace_insert_normal(const struct lu_env *env,
        struct lu_attr                  *la     = &info->lti_la;
        struct dt_insert_rec            *rec    = &info->lti_dt_rec;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       /* The child and its name may be on different MDTs. */
+       const struct lu_fid             *pfid   = lfsck_dto2fid(parent);
+       const struct lu_fid             *cfid   = lfsck_dto2fid(child);
        struct dt_device                *dev    = lfsck->li_next;
        struct thandle                  *th     = NULL;
-       struct lustre_handle             lh     = { 0 };
+       struct lfsck_lock_handle        *llh    = &info->lti_llh;
        int                              rc     = 0;
        ENTRY;
 
+       /* @parent/@child may be based on lfsck->li_bottom,
+        * but here we need the object based on the lfsck->li_next. */
+
+       parent = lfsck_object_locate(dev, parent);
+       if (IS_ERR(parent))
+               GOTO(log, rc = PTR_ERR(parent));
+
        if (unlikely(!dt_try_as_dir(env, parent)))
                GOTO(log, rc = -ENOTDIR);
 
+       child = lfsck_object_locate(dev, child);
+       if (IS_ERR(child))
+               GOTO(log, rc = PTR_ERR(child));
+
        if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
                GOTO(log, rc = 1);
 
-       /* Hold update lock on the parent to prevent others to access. */
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       rc = lfsck_lock(env, lfsck, parent, name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                GOTO(log, rc);
 
@@ -881,7 +1155,7 @@ static int lfsck_namespace_insert_normal(const struct lu_env *env,
                GOTO(unlock, rc = PTR_ERR(th));
 
        rec->rec_type = lfsck_object_type(child) & S_IFMT;
-       rec->rec_fid = lfsck_dto2fid(child);
+       rec->rec_fid = cfid;
        rc = dt_declare_insert(env, parent, (const struct dt_rec *)rec,
                               (const struct dt_key *)name, th);
        if (rc != 0)
@@ -900,12 +1174,16 @@ static int lfsck_namespace_insert_normal(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
+       rc = dt_declare_attr_set(env, child, la, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
        rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
        rc = dt_insert(env, parent, (const struct dt_rec *)rec,
-                      (const struct dt_key *)name, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)name, th, 1);
        if (rc != 0)
                GOTO(stop, rc);
 
@@ -918,7 +1196,11 @@ static int lfsck_namespace_insert_normal(const struct lu_env *env,
        }
 
        la->la_ctime = cfs_time_current_sec();
-       rc = dt_attr_set(env, parent, la, th, BYPASS_CAPA);
+       rc = dt_attr_set(env, parent, la, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rc = dt_attr_set(env, child, la, th);
 
        GOTO(stop, rc = (rc == 0 ? 1 : rc));
 
@@ -926,14 +1208,13 @@ stop:
        dt_trans_stop(env, dev, th);
 
 unlock:
-       lfsck_ibits_unlock(&lh, LCK_EX);
+       lfsck_unlock(llh);
 
 log:
        CDEBUG(D_LFSCK, "%s: namespace LFSCK insert object "DFID" with "
               "the name %s and type %o to the parent "DFID": rc = %d\n",
-              lfsck_lfsck2name(lfsck), PFID(lfsck_dto2fid(child)), name,
-              lfsck_object_type(child) & S_IFMT,
-              PFID(lfsck_dto2fid(parent)), rc);
+              lfsck_lfsck2name(lfsck), PFID(cfid), name,
+              lfsck_object_type(child) & S_IFMT, PFID(pfid), rc);
 
        if (rc != 0) {
                struct lfsck_namespace *ns = com->lc_file_ram;
@@ -946,103 +1227,368 @@ log:
        return rc;
 }
 
-static int lfsck_namespace_create_orphan(const struct lu_env *env,
-                                        struct lfsck_component *com,
-                                        struct dt_object *orphan)
-{
-       /* XXX: TBD */
-       return 0;
-}
-
 /**
- * Remove the specified entry from the linkEA.
+ * Create the specified orphan directory.
  *
- * Locate the linkEA entry with the given @cname and @pfid, then
- * remove this entry or the other entries those are repeated with
- * this entry.
+ * For the case that the parent MDT-object stored in some MDT-object's
+ * linkEA entry is lost, the LFSCK will re-create the parent object as
+ * an orphan and insert it into .lustre/lost+found/MDTxxxx/ directory
+ * with the name ${FID}-P-${conflict_version}.
  *
  * \param[in] env      pointer to the thread context
  * \param[in] com      pointer to the lfsck component
- * \param[in] obj      pointer to the dt_object to be handled
- * \param[in,out]ldata  pointer to the buffer that holds the linkEA
- * \param[in] cname    the name for the child in the parent directory
- * \param[in] pfid     the parent directory's FID for the linkEA
- * \param[in] next     if true, then remove the first found linkEA
- *                     entry, and move the ldata->ld_lee to next entry
+ * \param[in] orphan   pointer to the orphan MDT-object to be created
+ * \param[in] lmv      pointer to master LMV EA that will be set to the orphan
  *
  * \retval             positive number for repaired cases
- * \retval             0 if nothing to be repaired
  * \retval             negative error number on failure
  */
-static int lfsck_namespace_shrink_linkea(const struct lu_env *env,
-                                        struct lfsck_component *com,
-                                        struct dt_object *obj,
-                                        struct linkea_data *ldata,
-                                        struct lu_name *cname,
-                                        struct lu_fid *pfid,
-                                        bool next)
+static int lfsck_namespace_create_orphan_dir(const struct lu_env *env,
+                                            struct lfsck_component *com,
+                                            struct dt_object *orphan,
+                                            struct lmv_mds_md_v1 *lmv)
 {
-       struct lfsck_instance           *lfsck     = com->lc_lfsck;
-       struct dt_device                *dev       = lfsck->li_bottom;
-       struct lfsck_bookmark           *bk        = &lfsck->li_bookmark_ram;
-       struct thandle                  *th        = NULL;
-       struct lustre_handle             lh        = { 0 };
-       struct linkea_data               ldata_new = { 0 };
+       struct lfsck_thread_info        *info   = lfsck_env_info(env);
+       struct lu_attr                  *la     = &info->lti_la;
+       struct dt_allocation_hint       *hint   = &info->lti_hint;
+       struct dt_object_format         *dof    = &info->lti_dof;
+       struct lu_name                  *cname  = &info->lti_name2;
+       struct dt_insert_rec            *rec    = &info->lti_dt_rec;
+       struct lmv_mds_md_v1            *lmv2   = &info->lti_lmv2;
+       const struct lu_fid             *cfid   = lfsck_dto2fid(orphan);
+       struct lu_fid                    tfid;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct dt_device                *dev    = lfsck_obj2dev(orphan);
+       struct dt_object                *parent = NULL;
+       struct thandle                  *th     = NULL;
+       struct lfsck_lock_handle        *llh    = &info->lti_llh;
+       struct linkea_data               ldata  = { NULL };
        struct lu_buf                    linkea_buf;
-       int                              rc        = 0;
+       struct lu_buf                    lmv_buf;
+       char                             name[32];
+       int                              namelen;
+       int                              idx    = 0;
+       int                              rc     = 0;
+       int                              rc1    = 0;
        ENTRY;
 
-       rc = lfsck_ibits_lock(env, lfsck, obj, &lh,
-                             MDS_INODELOCK_UPDATE |
-                             MDS_INODELOCK_XATTR, LCK_EX);
+       LASSERT(!dt_object_exists(orphan));
+
+       cname->ln_name = NULL;
+       if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
+               GOTO(log, rc = 1);
+
+       if (dt_object_remote(orphan)) {
+               LASSERT(lfsck->li_lpf_root_obj != NULL);
+
+               idx = lfsck_find_mdt_idx_by_fid(env, lfsck, cfid);
+               if (idx < 0)
+                       GOTO(log, rc = idx);
+
+               snprintf(name, 8, "MDT%04x", idx);
+               rc = dt_lookup(env, lfsck->li_lpf_root_obj,
+                              (struct dt_rec *)&tfid,
+                              (const struct dt_key *)name);
+               if (rc != 0)
+                       GOTO(log, rc = (rc == -ENOENT ? -ENXIO : rc));
+
+               parent = lfsck_object_find_bottom(env, lfsck, &tfid);
+               if (IS_ERR(parent))
+                       GOTO(log, rc = PTR_ERR(parent));
+
+               if (unlikely(!dt_try_as_dir(env, parent)))
+                       GOTO(log, rc = -ENOTDIR);
+       } else {
+               if (unlikely(lfsck->li_lpf_obj == NULL))
+                       GOTO(log, rc = -ENXIO);
+
+               parent = lfsck->li_lpf_obj;
+       }
+
+       dev = lfsck_find_dev_by_fid(env, lfsck, cfid);
+       if (IS_ERR(dev))
+               GOTO(log, rc = PTR_ERR(dev));
+
+       idx = 0;
+
+again:
+       do {
+               namelen = snprintf(name, 31, DFID"-P-%d",
+                                  PFID(cfid), idx++);
+               rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                              (const struct dt_key *)name);
+               if (rc != 0 && rc != -ENOENT)
+                       GOTO(log, rc);
+       } while (rc == 0);
+
+       rc = lfsck_lock(env, lfsck, parent, name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                GOTO(log, rc);
 
-       if (next)
-               linkea_del_buf(ldata, cname);
-       else
-               lfsck_namespace_filter_linkea_entry(ldata, cname, pfid,
-                                                   true);
-       lfsck_buf_init(&linkea_buf, ldata->ld_buf->lb_buf,
-                      ldata->ld_leh->leh_len);
+       /* Re-check whether the name conflict with othrs after taken
+        * the ldlm lock. */
+       rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                      (const struct dt_key *)name);
+       if (unlikely(rc == 0)) {
+               lfsck_unlock(llh);
+               goto again;
+       }
+
+       if (rc != -ENOENT)
+               GOTO(unlock1, rc);
+
+       cname->ln_name = name;
+       cname->ln_namelen = namelen;
+
+       memset(la, 0, sizeof(*la));
+       la->la_mode = S_IFDIR | 0700;
+       la->la_valid = LA_TYPE | LA_MODE | LA_UID | LA_GID |
+                      LA_ATIME | LA_MTIME | LA_CTIME;
+
+       orphan->do_ops->do_ah_init(env, hint, parent, orphan,
+                                  la->la_mode & S_IFMT);
+
+       memset(dof, 0, sizeof(*dof));
+       dof->dof_type = dt_mode_to_dft(S_IFDIR);
+
+       rc = linkea_links_new(&ldata, &info->lti_linkea_buf2,
+                             cname, lfsck_dto2fid(parent));
+       if (rc != 0)
+               GOTO(unlock1, rc);
 
-again:
        th = dt_trans_create(env, dev);
        if (IS_ERR(th))
                GOTO(unlock1, rc = PTR_ERR(th));
 
-       rc = dt_declare_xattr_set(env, obj, &linkea_buf,
-                                 XATTR_NAME_LINK, 0, th);
+       /* Sync the remote transaction to guarantee that the subsequent
+        * lock against the @orphan can find the @orphan in time. */
+       if (dt_object_remote(orphan))
+               th->th_sync = 1;
+
+       rc = dt_declare_create(env, orphan, la, hint, dof, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_trans_start_local(env, dev, th);
+       if (unlikely(!dt_try_as_dir(env, orphan)))
+               GOTO(stop, rc = -ENOTDIR);
+
+       rc = dt_declare_ref_add(env, orphan, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       dt_write_lock(env, obj, 0);
-       if (unlikely(lfsck_is_dead_obj(obj)))
-               GOTO(unlock2, rc = -ENOENT);
-
-       rc = lfsck_links_read2(env, obj, &ldata_new);
+       rec->rec_type = S_IFDIR;
+       rec->rec_fid = cfid;
+       rc = dt_declare_insert(env, orphan, (const struct dt_rec *)rec,
+                              (const struct dt_key *)dot, th);
        if (rc != 0)
-               GOTO(unlock2, rc);
+               GOTO(stop, rc);
 
-       /* The specified linkEA entry has been removed by race. */
-       rc = linkea_links_find(&ldata_new, cname, pfid);
+       rec->rec_fid = lfsck_dto2fid(parent);
+       rc = dt_declare_insert(env, orphan, (const struct dt_rec *)rec,
+                              (const struct dt_key *)dotdot, th);
        if (rc != 0)
-               GOTO(unlock2, rc = 0);
+               GOTO(stop, rc);
 
-       if (bk->lb_param & LPF_DRYRUN)
-               GOTO(unlock2, rc = 1);
+       if (lmv != NULL) {
+               lmv->lmv_magic = LMV_MAGIC;
+               lmv->lmv_master_mdt_index = lfsck_dev_idx(lfsck);
+               lfsck_lmv_header_cpu_to_le(lmv2, lmv);
+               lfsck_buf_init(&lmv_buf, lmv2, sizeof(*lmv2));
+               rc = dt_declare_xattr_set(env, orphan, &lmv_buf,
+                                         XATTR_NAME_LMV, 0, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       }
 
-       if (next)
-               linkea_del_buf(&ldata_new, cname);
-       else
+       lfsck_buf_init(&linkea_buf, ldata.ld_buf->lb_buf,
+                      ldata.ld_leh->leh_len);
+       rc = dt_declare_xattr_set(env, orphan, &linkea_buf,
+                                 XATTR_NAME_LINK, 0, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rec->rec_fid = cfid;
+       rc = dt_declare_insert(env, parent, (const struct dt_rec *)rec,
+                              (const struct dt_key *)name, th);
+       if (rc == 0)
+               rc = dt_declare_ref_add(env, parent, th);
+
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       dt_write_lock(env, orphan, 0);
+       rc = dt_create(env, orphan, la, hint, dof, th);
+       if (rc != 0)
+               GOTO(unlock2, rc);
+
+       rc = dt_ref_add(env, orphan, th);
+       if (rc != 0)
+               GOTO(unlock2, rc);
+
+       rec->rec_fid = cfid;
+       rc = dt_insert(env, orphan, (const struct dt_rec *)rec,
+                      (const struct dt_key *)dot, th, 1);
+       if (rc != 0)
+               GOTO(unlock2, rc);
+
+       rec->rec_fid = lfsck_dto2fid(parent);
+       rc = dt_insert(env, orphan, (const struct dt_rec *)rec,
+                      (const struct dt_key *)dotdot, th, 1);
+       if (rc != 0)
+               GOTO(unlock2, rc);
+
+       if (lmv != NULL) {
+               rc = dt_xattr_set(env, orphan, &lmv_buf, XATTR_NAME_LMV, 0, th);
+               if (rc != 0)
+                       GOTO(unlock2, rc);
+       }
+
+       rc = dt_xattr_set(env, orphan, &linkea_buf,
+                         XATTR_NAME_LINK, 0, th);
+       dt_write_unlock(env, orphan);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rec->rec_fid = cfid;
+       rc = dt_insert(env, parent, (const struct dt_rec *)rec,
+                      (const struct dt_key *)name, th, 1);
+       if (rc == 0) {
+               dt_write_lock(env, parent, 0);
+               rc = dt_ref_add(env, parent, th);
+               dt_write_unlock(env, parent);
+       }
+
+       GOTO(stop, rc = (rc == 0 ? 1 : rc));
+
+unlock2:
+       dt_write_unlock(env, orphan);
+
+stop:
+       rc1 = dt_trans_stop(env, dev, th);
+       if (rc1 != 0 && rc > 0)
+               rc = rc1;
+
+unlock1:
+       lfsck_unlock(llh);
+
+log:
+       CDEBUG(D_LFSCK, "%s: namespace LFSCK create orphan dir for "
+              "the object "DFID", name = %s: rc = %d\n",
+              lfsck_lfsck2name(lfsck), PFID(cfid),
+              cname->ln_name != NULL ? cname->ln_name : "<NULL>", rc);
+
+       if (parent != NULL && !IS_ERR(parent) && parent != lfsck->li_lpf_obj)
+               lfsck_object_put(env, parent);
+
+       if (rc != 0)
+               ns->ln_flags |= LF_INCONSISTENT;
+
+       return rc;
+}
+
+/**
+ * Remove the specified entry from the linkEA.
+ *
+ * Locate the linkEA entry with the given @cname and @pfid, then
+ * remove this entry or the other entries those are repeated with
+ * this entry.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] obj      pointer to the dt_object to be handled
+ * \param[in,out]ldata  pointer to the buffer that holds the linkEA
+ * \param[in] cname    the name for the child in the parent directory
+ * \param[in] pfid     the parent directory's FID for the linkEA
+ * \param[in] next     if true, then remove the first found linkEA
+ *                     entry, and move the ldata->ld_lee to next entry
+ *
+ * \retval             positive number for repaired cases
+ * \retval             0 if nothing to be repaired
+ * \retval             negative error number on failure
+ */
+static int lfsck_namespace_shrink_linkea(const struct lu_env *env,
+                                        struct lfsck_component *com,
+                                        struct dt_object *obj,
+                                        struct linkea_data *ldata,
+                                        struct lu_name *cname,
+                                        struct lu_fid *pfid,
+                                        bool next)
+{
+       struct lfsck_instance           *lfsck     = com->lc_lfsck;
+       struct dt_device                *dev       = lfsck_obj2dev(obj);
+       struct lfsck_bookmark           *bk        = &lfsck->li_bookmark_ram;
+       struct thandle                  *th        = NULL;
+       struct lustre_handle             lh        = { 0 };
+       struct linkea_data               ldata_new = { NULL };
+       struct lu_buf                    linkea_buf;
+       int                              buflen    = 0;
+       int                              rc        = 0;
+       ENTRY;
+
+       rc = lfsck_ibits_lock(env, lfsck, obj, &lh,
+                             MDS_INODELOCK_UPDATE | MDS_INODELOCK_XATTR,
+                             LCK_EX);
+       if (rc != 0)
+               GOTO(log, rc);
+
+       if (next)
+               lfsck_linkea_del_buf(ldata, cname);
+       else
+               lfsck_namespace_filter_linkea_entry(ldata, cname, pfid,
+                                                   true);
+       if (ldata->ld_leh->leh_reccount > 0 ||
+           unlikely(ldata->ld_leh->leh_overflow_time)) {
+               lfsck_buf_init(&linkea_buf, ldata->ld_buf->lb_buf,
+                              ldata->ld_leh->leh_len);
+               buflen = linkea_buf.lb_len;
+       }
+
+again:
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(unlock1, rc = PTR_ERR(th));
+
+       if (buflen != 0)
+               rc = dt_declare_xattr_set(env, obj, &linkea_buf,
+                                         XATTR_NAME_LINK, 0, th);
+       else
+               rc = dt_declare_xattr_del(env, obj, XATTR_NAME_LINK, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       dt_write_lock(env, obj, 0);
+       if (unlikely(lfsck_is_dead_obj(obj)))
+               GOTO(unlock2, rc = -ENOENT);
+
+       rc = lfsck_links_read2_with_rec(env, obj, &ldata_new);
+       if (rc)
+               GOTO(unlock2, rc = (rc == -ENODATA ? 0 : rc));
+
+       /* The specified linkEA entry has been removed by race. */
+       rc = linkea_links_find(&ldata_new, cname, pfid);
+       if (rc != 0)
+               GOTO(unlock2, rc = 0);
+
+       if (bk->lb_param & LPF_DRYRUN)
+               GOTO(unlock2, rc = 1);
+
+       if (next)
+               lfsck_linkea_del_buf(&ldata_new, cname);
+       else
                lfsck_namespace_filter_linkea_entry(&ldata_new, cname, pfid,
                                                    true);
 
-       if (linkea_buf.lb_len < ldata_new.ld_leh->leh_len) {
+       if (buflen < ldata_new.ld_leh->leh_len) {
                dt_write_unlock(env, obj);
                dt_trans_stop(env, dev, th);
                lfsck_buf_init(&linkea_buf, ldata_new.ld_buf->lb_buf,
@@ -1050,10 +1596,11 @@ again:
                goto again;
        }
 
-       lfsck_buf_init(&linkea_buf, ldata_new.ld_buf->lb_buf,
-                      ldata_new.ld_leh->leh_len);
-       rc = dt_xattr_set(env, obj, &linkea_buf,
-                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
+       if (ldata_new.ld_leh->leh_reccount > 0 ||
+           unlikely(ldata->ld_leh->leh_overflow_time))
+               rc = lfsck_links_write(env, obj, &ldata_new, th);
+       else
+               rc = dt_xattr_del(env, obj, XATTR_NAME_LINK, th);
 
        GOTO(unlock2, rc = (rc == 0 ? 1 : rc));
 
@@ -1109,20 +1656,21 @@ static int lfsck_namespace_shrink_linkea_cond(const struct lu_env *env,
                                              struct lu_name *cname,
                                              struct lu_fid *pfid)
 {
-       struct lu_fid           *cfid   = &lfsck_env_info(env)->lti_fid3;
-       struct lustre_handle     lh     = { 0 };
-       int                      rc;
+       struct lfsck_thread_info *info  = lfsck_env_info(env);
+       struct lu_fid            *cfid  = &info->lti_fid3;
+       struct lfsck_lock_handle *llh   = &info->lti_llh;
+       int                       rc;
        ENTRY;
 
-       rc = lfsck_ibits_lock(env, com->lc_lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       rc = lfsck_lock(env, com->lc_lfsck, parent, cname->ln_name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PR);
        if (rc != 0)
                RETURN(rc);
 
        dt_read_lock(env, parent, 0);
        if (unlikely(lfsck_is_dead_obj(parent))) {
                dt_read_unlock(env, parent);
-               lfsck_ibits_unlock(&lh, LCK_EX);
+               lfsck_unlock(llh);
                rc = lfsck_namespace_shrink_linkea(env, com, child, ldata,
                                                   cname, pfid, true);
 
@@ -1130,8 +1678,7 @@ static int lfsck_namespace_shrink_linkea_cond(const struct lu_env *env,
        }
 
        rc = dt_lookup(env, parent, (struct dt_rec *)cfid,
-                      (const struct dt_key *)cname->ln_name,
-                      BYPASS_CAPA);
+                      (const struct dt_key *)cname->ln_name);
        dt_read_unlock(env, parent);
 
        /* It is safe to release the ldlm lock, because when the logic come
@@ -1141,7 +1688,7 @@ static int lfsck_namespace_shrink_linkea_cond(const struct lu_env *env,
         * has removed the specified linkEA entry by race, then it is OK,
         * because the subsequent lfsck_namespace_shrink_linkea() can handle
         * such case. */
-       lfsck_ibits_unlock(&lh, LCK_EX);
+       lfsck_unlock(llh);
        if (rc == -ENOENT) {
                rc = lfsck_namespace_shrink_linkea(env, com, child, ldata,
                                                   cname, pfid, true);
@@ -1196,23 +1743,35 @@ static int lfsck_namespace_replace_cond(const struct lu_env *env,
                                        const struct lu_name *cname)
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
-       struct lu_fid                   *tfid   = &info->lti_fid5;
        struct lu_attr                  *la     = &info->lti_la;
        struct dt_insert_rec            *rec    = &info->lti_dt_rec;
+       struct lu_fid                    tfid;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       /* The child and its name may be on different MDTs. */
        struct dt_device                *dev    = lfsck->li_next;
        const char                      *name   = cname->ln_name;
-       struct dt_object                *obj    = NULL;
-       struct lustre_handle             plh    = { 0 };
+       const struct lu_fid             *pfid   = lfsck_dto2fid(parent);
+       struct dt_object                *cobj   = NULL;
+       struct lfsck_lock_handle        *pllh   = &info->lti_llh;
        struct lustre_handle             clh    = { 0 };
-       struct linkea_data               ldata  = { 0 };
+       struct linkea_data               ldata  = { NULL };
        struct thandle                  *th     = NULL;
        bool                             exist  = true;
        int                              rc     = 0;
        ENTRY;
 
-       rc = lfsck_ibits_lock(env, lfsck, parent, &plh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       /* @parent/@child may be based on lfsck->li_bottom,
+        * but here we need the object based on the lfsck->li_next. */
+
+       parent = lfsck_object_locate(dev, parent);
+       if (IS_ERR(parent))
+               GOTO(log, rc = PTR_ERR(parent));
+
+       if (unlikely(!dt_try_as_dir(env, parent)))
+               GOTO(log, rc = -ENOTDIR);
+
+       rc = lfsck_lock(env, lfsck, parent, name, pllh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                GOTO(log, rc);
 
@@ -1221,9 +1780,9 @@ static int lfsck_namespace_replace_cond(const struct lu_env *env,
                goto replace;
        }
 
-       obj = lfsck_object_find(env, lfsck, cfid);
-       if (IS_ERR(obj)) {
-               rc = PTR_ERR(obj);
+       cobj = lfsck_object_find_by_dev(env, dev, cfid);
+       if (IS_ERR(cobj)) {
+               rc = PTR_ERR(cobj);
                if (rc == -ENOENT) {
                        exist = false;
                        goto replace;
@@ -1232,13 +1791,13 @@ static int lfsck_namespace_replace_cond(const struct lu_env *env,
                GOTO(log, rc);
        }
 
-       if (!dt_object_exists(obj)) {
+       if (!dt_object_exists(cobj)) {
                exist = false;
                goto replace;
        }
 
-       rc = dt_lookup(env, parent, (struct dt_rec *)tfid,
-                      (const struct dt_key *)name, BYPASS_CAPA);
+       rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                      (const struct dt_key *)name);
        if (rc == -ENOENT) {
                exist = false;
                goto replace;
@@ -1248,22 +1807,23 @@ static int lfsck_namespace_replace_cond(const struct lu_env *env,
                GOTO(log, rc);
 
        /* Someone changed the name entry, cannot replace it. */
-       if (!lu_fid_eq(cfid, tfid))
+       if (!lu_fid_eq(cfid, &tfid))
                GOTO(log, rc = 0);
 
        /* lock the object to be destroyed. */
-       rc = lfsck_ibits_lock(env, lfsck, obj, &clh,
+       rc = lfsck_ibits_lock(env, lfsck, cobj, &clh,
                              MDS_INODELOCK_UPDATE |
-                             MDS_INODELOCK_XATTR, LCK_EX);
+                             MDS_INODELOCK_UPDATE | MDS_INODELOCK_XATTR,
+                             LCK_EX);
        if (rc != 0)
                GOTO(log, rc);
 
-       if (unlikely(lfsck_is_dead_obj(obj))) {
+       if (unlikely(lfsck_is_dead_obj(cobj))) {
                exist = false;
                goto replace;
        }
 
-       rc = dt_attr_get(env, obj, la, BYPASS_CAPA);
+       rc = dt_attr_get(env, cobj, la);
        if (rc != 0)
                GOTO(log, rc);
 
@@ -1273,8 +1833,7 @@ static int lfsck_namespace_replace_cond(const struct lu_env *env,
                GOTO(log, rc);
 
        if (S_ISREG(la->la_mode)) {
-               rc = dt_xattr_get(env, obj, &LU_BUF_NULL, XATTR_NAME_LOV,
-                                 BYPASS_CAPA);
+               rc = dt_xattr_get(env, cobj, &LU_BUF_NULL, XATTR_NAME_LOV);
                /* If someone has created related OST-object(s),
                 * then keep it. */
                if ((rc > 0) || (rc < 0 && rc != -ENODATA))
@@ -1283,7 +1842,7 @@ static int lfsck_namespace_replace_cond(const struct lu_env *env,
 
 replace:
        dt_read_lock(env, child, 0);
-       rc = lfsck_links_read2(env, child, &ldata);
+       rc = lfsck_links_read2_with_rec(env, child, &ldata);
        dt_read_unlock(env, child);
 
        /* Someone changed the child, no need to replace. */
@@ -1293,7 +1852,7 @@ replace:
        if (rc != 0)
                GOTO(log, rc);
 
-       rc = linkea_links_find(&ldata, cname, lfsck_dto2fid(parent));
+       rc = linkea_links_find(&ldata, cname, pfid);
        /* Someone moved the child, no need to replace. */
        if (rc != 0)
                GOTO(log, rc = 0);
@@ -1306,7 +1865,7 @@ replace:
                GOTO(log, rc = PTR_ERR(th));
 
        if (exist) {
-               rc = dt_declare_destroy(env, obj, th);
+               rc = dt_declare_destroy(env, cobj, th);
                if (rc != 0)
                        GOTO(stop, rc);
        }
@@ -1322,22 +1881,23 @@ replace:
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_trans_start(env, dev, th);
+       rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
        if (exist) {
-               rc = dt_destroy(env, obj, th);
+               rc = dt_destroy(env, cobj, th);
                if (rc != 0)
                        GOTO(stop, rc);
        }
 
        /* The old name entry maybe not exist. */
-       dt_delete(env, parent, (const struct dt_key *)name, th,
-                 BYPASS_CAPA);
+       rc = dt_delete(env, parent, (const struct dt_key *)name, th);
+       if (rc != 0 && rc != -ENOENT)
+               GOTO(stop, rc);
 
        rc = dt_insert(env, parent, (const struct dt_rec *)rec,
-                      (const struct dt_key *)name, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)name, th, 1);
 
        GOTO(stop, rc = (rc == 0 ? 1 : rc));
 
@@ -1346,16 +1906,16 @@ stop:
 
 log:
        lfsck_ibits_unlock(&clh, LCK_EX);
-       lfsck_ibits_unlock(&plh, LCK_EX);
-       if (obj != NULL && !IS_ERR(obj))
-               lfsck_object_put(env, obj);
+       lfsck_unlock(pllh);
+
+       if (cobj != NULL && !IS_ERR(cobj))
+               lfsck_object_put(env, cobj);
 
        CDEBUG(D_LFSCK, "%s: namespace LFSCK conditionally destroy the "
               "object "DFID" because of conflict with the object "DFID
               " under the parent "DFID" with name %s: rc = %d\n",
               lfsck_lfsck2name(lfsck), PFID(cfid),
-              PFID(lfsck_dto2fid(child)), PFID(lfsck_dto2fid(parent)),
-              name, rc);
+              PFID(lfsck_dto2fid(child)), PFID(pfid), name, rc);
 
        return rc;
 }
@@ -1380,14 +1940,12 @@ int lfsck_namespace_rebuild_linkea(const struct lu_env *env,
                                   struct linkea_data *ldata)
 {
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
-       struct dt_device                *dev    = lfsck->li_bottom;
+       struct dt_device                *dev    = lfsck_obj2dev(obj);
        struct thandle                  *th     = NULL;
        struct lu_buf                    linkea_buf;
        int                              rc     = 0;
        ENTRY;
 
-       LASSERT(!dt_object_remote(obj));
-
        th = dt_trans_create(env, dev);
        if (IS_ERR(th))
                GOTO(log, rc = PTR_ERR(th));
@@ -1411,7 +1969,7 @@ int lfsck_namespace_rebuild_linkea(const struct lu_env *env,
                GOTO(unlock, rc = 1);
 
        rc = dt_xattr_set(env, obj, &linkea_buf,
-                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
+                         XATTR_NAME_LINK, 0, th);
 
        GOTO(unlock, rc = (rc == 0 ? 1 : rc));
 
@@ -1465,20 +2023,30 @@ int lfsck_namespace_repair_dirent(const struct lu_env *env,
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
        struct dt_insert_rec            *rec    = &info->lti_dt_rec;
+       const struct lu_fid             *pfid   = lfsck_dto2fid(parent);
        const struct lu_fid             *cfid   = lfsck_dto2fid(child);
-       struct lu_fid                   *tfid   = &info->lti_fid5;
+       struct lu_fid                    tfid;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
        struct dt_device                *dev    = lfsck->li_next;
        struct thandle                  *th     = NULL;
+       struct lfsck_lock_handle        *llh    = &info->lti_llh;
        struct lustre_handle             lh     = { 0 };
        int                              rc     = 0;
        ENTRY;
 
+       parent = lfsck_object_locate(dev, parent);
+       if (IS_ERR(parent))
+               GOTO(log, rc = PTR_ERR(parent));
+
        if (unlikely(!dt_try_as_dir(env, parent)))
                GOTO(log, rc = -ENOTDIR);
 
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       if (!update || strcmp(name, name2) == 0)
+               rc = lfsck_lock(env, lfsck, parent, name, llh,
+                               MDS_INODELOCK_UPDATE, LCK_PW);
+       else
+               rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
+                                     MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                GOTO(log, rc);
 
@@ -1500,19 +2068,20 @@ int lfsck_namespace_repair_dirent(const struct lu_env *env,
                        GOTO(stop, rc);
        }
 
-       if (dec) {
+       if (dec && S_ISDIR(type)) {
                rc = dt_declare_ref_del(env, parent, th);
                if (rc != 0)
                        GOTO(stop, rc);
        }
 
-       rc = dt_trans_start(env, dev, th);
+       rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
+
        dt_write_lock(env, parent, 0);
-       rc = dt_lookup(env, parent, (struct dt_rec *)tfid,
-                      (const struct dt_key *)name, BYPASS_CAPA);
+       rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                      (const struct dt_key *)name);
        /* Someone has removed the bad name entry by race. */
        if (rc == -ENOENT)
                GOTO(unlock2, rc = 0);
@@ -1522,27 +2091,25 @@ int lfsck_namespace_repair_dirent(const struct lu_env *env,
 
        /* Someone has removed the bad name entry and reused it for other
         * object by race. */
-       if (!lu_fid_eq(tfid, cfid))
+       if (!lu_fid_eq(&tfid, cfid))
                GOTO(unlock2, rc = 0);
 
        if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
                GOTO(unlock2, rc = 1);
 
-       rc = dt_delete(env, parent, (const struct dt_key *)name, th,
-                      BYPASS_CAPA);
+       rc = dt_delete(env, parent, (const struct dt_key *)name, th);
        if (rc != 0)
                GOTO(unlock2, rc);
 
        if (update) {
                rc = dt_insert(env, parent,
                               (const struct dt_rec *)rec,
-                              (const struct dt_key *)name2, th,
-                              BYPASS_CAPA, 1);
+                              (const struct dt_key *)name2, th, 1);
                if (rc != 0)
                        GOTO(unlock2, rc);
        }
 
-       if (dec) {
+       if (dec && S_ISDIR(type)) {
                rc = dt_ref_del(env, parent, th);
                if (rc != 0)
                        GOTO(unlock2, rc);
@@ -1557,21 +2124,23 @@ stop:
        dt_trans_stop(env, dev, th);
 
        /* We are not sure whether the child will become orphan or not.
-        * Record it in the LFSCK tracing file for further checking in
+        * Record it in the LFSCK trace file for further checking in
         * the second-stage scanning. */
        if (!update && !dec && rc == 0)
                lfsck_namespace_trace_update(env, com, cfid,
                                             LNTF_CHECK_LINKEA, true);
 
 unlock1:
-       lfsck_ibits_unlock(&lh, LCK_EX);
+       /* It is harmless even if unlock the unused lock_handle */
+       lfsck_ibits_unlock(&lh, LCK_PW);
+       lfsck_unlock(llh);
 
 log:
        CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant found bad name "
               "entry for: parent "DFID", child "DFID", name %s, type "
               "in name entry %o, type claimed by child %o. repair it "
-              "by %s with new name2 %s: rc = %d\n", lfsck_lfsck2name(lfsck),
-              PFID(lfsck_dto2fid(parent)), PFID(lfsck_dto2fid(child)),
+              "by %s with new name2 %s: rc = %d\n",
+              lfsck_lfsck2name(lfsck), PFID(pfid), PFID(cfid),
               name, type, update ? lfsck_object_type(child) : 0,
               update ? "updating" : "removing", name2, rc);
 
@@ -1611,9 +2180,9 @@ static int lfsck_namespace_repair_unmatched_pairs(const struct lu_env *env,
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
        struct dt_insert_rec            *rec    = &info->lti_dt_rec;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
-       struct dt_device                *dev    = lfsck->li_bottom;
+       struct dt_device                *dev    = lfsck_obj2dev(obj);
        struct thandle                  *th     = NULL;
-       struct linkea_data               ldata  = { 0 };
+       struct linkea_data               ldata  = { NULL };
        struct lu_buf                    linkea_buf;
        int                              rc     = 0;
        ENTRY;
@@ -1621,11 +2190,7 @@ static int lfsck_namespace_repair_unmatched_pairs(const struct lu_env *env,
        LASSERT(!dt_object_remote(obj));
        LASSERT(S_ISDIR(lfsck_object_type(obj)));
 
-       rc = linkea_data_new(&ldata, &info->lti_big_buf);
-       if (rc != 0)
-               GOTO(log, rc);
-
-       rc = linkea_add_buf(&ldata, cname, pfid);
+       rc = linkea_links_new(&ldata, &info->lti_big_buf, cname, pfid);
        if (rc != 0)
                GOTO(log, rc);
 
@@ -1664,16 +2229,14 @@ static int lfsck_namespace_repair_unmatched_pairs(const struct lu_env *env,
                GOTO(unlock, rc = 1);
 
        /* The old ".." name entry maybe not exist. */
-       dt_delete(env, obj, (const struct dt_key *)dotdot, th,
-                 BYPASS_CAPA);
+       dt_delete(env, obj, (const struct dt_key *)dotdot, th);
 
        rc = dt_insert(env, obj, (const struct dt_rec *)rec,
-                      (const struct dt_key *)dotdot, th, BYPASS_CAPA, 1);
+                      (const struct dt_key *)dotdot, th, 1);
        if (rc != 0)
                GOTO(unlock, rc);
 
-       rc = dt_xattr_set(env, obj, &linkea_buf,
-                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
+       rc = lfsck_links_write(env, obj, &ldata, th);
 
        GOTO(unlock, rc = (rc == 0 ? 1 : rc));
 
@@ -1727,6 +2290,7 @@ lfsck_namespace_dsd_orphan(const struct lu_env *env,
                           enum lfsck_namespace_inconsistency_type *type)
 {
        struct lfsck_thread_info *info = lfsck_env_info(env);
+       struct lfsck_namespace   *ns   = com->lc_file_ram;
        int                       rc;
        ENTRY;
 
@@ -1737,6 +2301,17 @@ lfsck_namespace_dsd_orphan(const struct lu_env *env,
                RETURN(rc);
 
        *type = LNIT_MUL_REF;
+
+       /* If the LFSCK is marked as LF_INCOMPLETE, then means some MDT has
+        * ever tried to verify some remote MDT-object that resides on this
+        * MDT, but this MDT failed to respond such request. So means there
+        * may be some remote name entry on other MDT that references this
+        * object with another name, so we cannot know whether this linkEA
+        * is valid or not. So keep it there and maybe resolved when next
+        * LFSCK run. */
+       if (ns->ln_flags & LF_INCOMPLETE)
+               RETURN(0);
+
        /* The unique linkEA is invalid, even if the ".." name entry may be
         * valid, we still cannot know via which name entry this directory
         * will be referenced. Then handle it as pure orphan. */
@@ -1766,6 +2341,7 @@ lfsck_namespace_dsd_orphan(const struct lu_env *env,
  * \param[out] type    to tell the caller what the inconsistency is
  * \param[in] retry    if found inconsistency, but the caller does not hold
  *                     ldlm lock on the @child, then set @retry as true
+ * \param[in] unknown  set if does not know how to repair the inconsistency
  *
  * \retval             positive number for repaired cases
  * \retval             0 if nothing to be repaired
@@ -1779,20 +2355,24 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                           struct linkea_data *ldata,
                           struct lustre_handle *lh,
                           enum lfsck_namespace_inconsistency_type *type,
-                          bool *retry)
+                          bool *retry, bool *unknown)
 {
        struct lfsck_thread_info *info          = lfsck_env_info(env);
        struct lu_name           *cname         = &info->lti_name;
        const struct lu_fid      *cfid          = lfsck_dto2fid(child);
-       struct lu_fid            *tfid          = &info->lti_fid3;
+       struct lu_fid             tfid;
+       struct lfsck_namespace   *ns            = com->lc_file_ram;
        struct lfsck_instance    *lfsck         = com->lc_lfsck;
        struct dt_object         *parent        = NULL;
+       struct lmv_mds_md_v1     *lmv;
        int                       rc            = 0;
        ENTRY;
 
-       lfsck_namespace_unpack_linkea_entry(ldata, cname, tfid, info->lti_key);
+       rc = lfsck_namespace_unpack_linkea_entry(ldata, cname, &tfid,
+                                                info->lti_key,
+                                                sizeof(info->lti_key));
        /* The unique linkEA entry with bad parent will be handled as orphan. */
-       if (!fid_is_sane(tfid)) {
+       if (rc != 0) {
                if (!lustre_handle_is_used(lh) && retry != NULL)
                        *retry = true;
                else
@@ -1802,7 +2382,7 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                GOTO(out, rc);
        }
 
-       parent = lfsck_object_find_bottom(env, lfsck, tfid);
+       parent = lfsck_object_find_bottom(env, lfsck, &tfid);
        if (IS_ERR(parent))
                GOTO(out, rc = PTR_ERR(parent));
 
@@ -1812,6 +2392,16 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
         * name entry the child will be referenced, since all known entries
         * have been verified during the first-stage scanning. */
        if (!dt_object_exists(parent)) {
+               /* If the LFSCK is marked as LF_INCOMPLETE, then means some MDT
+                * has ever tried to verify some remote MDT-object that resides
+                * on this MDT, but this MDT failed to respond such request. So
+                * means there may be some remote name entry on other MDT that
+                * references this object with another name, so we cannot know
+                * whether this linkEA is valid or not. So keep it there and
+                * maybe resolved when next LFSCK run. */
+               if (ns->ln_flags & LF_INCOMPLETE)
+                       GOTO(out, rc = 0);
+
                if (!lustre_handle_is_used(lh) && retry != NULL) {
                        *retry = true;
 
@@ -1819,8 +2409,35 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                }
 
                lfsck_ibits_unlock(lh, LCK_EX);
+
+lost_parent:
+               lmv = &info->lti_lmv;
+               rc = lfsck_read_stripe_lmv(env, child, lmv);
+               if (rc != 0 && rc != -ENODATA)
+                       GOTO(out, rc);
+
+               if (rc == -ENODATA || lmv->lmv_magic != LMV_MAGIC_STRIPE) {
+                       lmv = NULL;
+               } else if (lfsck_shard_name_to_index(env,
+                                       cname->ln_name, cname->ln_namelen,
+                                       S_IFDIR, cfid) < 0) {
+                       /* It is an invalid name entry, we
+                        * cannot trust the parent also. */
+                       rc = lfsck_namespace_shrink_linkea(env, com, child,
+                                               ldata, cname, &tfid, true);
+                       if (rc < 0)
+                               GOTO(out, rc);
+
+                       snprintf(info->lti_tmpbuf, sizeof(info->lti_tmpbuf),
+                                "-"DFID, PFID(pfid));
+                       rc = lfsck_namespace_insert_orphan(env, com, child,
+                                               info->lti_tmpbuf, "S", NULL);
+
+                       GOTO(out, rc);
+               }
+
                /* Create the lost parent as an orphan. */
-               rc = lfsck_namespace_create_orphan(env, com, parent);
+               rc = lfsck_namespace_create_orphan_dir(env, com, parent, lmv);
                if (rc >= 0) {
                        /* Add the missing name entry to the parent. */
                        rc = lfsck_namespace_insert_normal(env, com, parent,
@@ -1836,7 +2453,7 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                                 * current system to be consistent. */
                                rc = lfsck_namespace_shrink_linkea(env,
                                                com, child, ldata,
-                                               cname, tfid, true);
+                                               cname, &tfid, true);
                                if (rc >= 0) {
                                        snprintf(info->lti_tmpbuf,
                                                 sizeof(info->lti_tmpbuf),
@@ -1849,7 +2466,7 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                }
 
                GOTO(out, rc);
-       }
+       } /* !dt_object_exists(parent) */
 
        /* The unique linkEA entry with bad parent will be handled as orphan. */
        if (unlikely(!dt_try_as_dir(env, parent))) {
@@ -1862,9 +2479,19 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                GOTO(out, rc);
        }
 
-       rc = dt_lookup(env, parent, (struct dt_rec *)tfid,
-                      (const struct dt_key *)cname->ln_name, BYPASS_CAPA);
+       rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                      (const struct dt_key *)cname->ln_name);
        if (rc == -ENOENT) {
+               /* If the LFSCK is marked as LF_INCOMPLETE, then means some MDT
+                * has ever tried to verify some remote MDT-object that resides
+                * on this MDT, but this MDT failed to respond such request. So
+                * means there may be some remote name entry on other MDT that
+                * references this object with another name, so we cannot know
+                * whether this linkEA is valid or not. So keep it there and
+                * maybe resolved when next LFSCK run. */
+               if (ns->ln_flags & LF_INCOMPLETE)
+                       GOTO(out, rc = 0);
+
                if (!lustre_handle_is_used(lh) && retry != NULL) {
                        *retry = true;
 
@@ -1872,9 +2499,36 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                }
 
                lfsck_ibits_unlock(lh, LCK_EX);
+               rc = lfsck_namespace_check_name(env, parent, child, cname);
+               if (rc == -ENOENT)
+                       goto lost_parent;
+
+               if (rc < 0)
+                       GOTO(out, rc);
+
+               /* It is an invalid name entry, drop it. */
+               if (unlikely(rc > 0)) {
+                       rc = lfsck_namespace_shrink_linkea(env, com, child,
+                                               ldata, cname, &tfid, true);
+                       if (rc >= 0) {
+                               snprintf(info->lti_tmpbuf,
+                                        sizeof(info->lti_tmpbuf),
+                                        "-"DFID, PFID(pfid));
+                               rc = lfsck_namespace_insert_orphan(env, com,
+                                       child, info->lti_tmpbuf, "D", NULL);
+                       }
+
+                       GOTO(out, rc);
+               }
+
                /* Add the missing name entry back to the namespace. */
                rc = lfsck_namespace_insert_normal(env, com, parent, child,
                                                   cname->ln_name);
+               if (unlikely(rc == -ESTALE))
+                       /* It may happen when the remote object has been
+                        * removed, but the local MDT is not aware of that. */
+                       goto lost_parent;
+
                if (unlikely(rc == -EEXIST)) {
                        /* Unfortunately, someone reused the name under the
                         * parent by race. So we have to remove the linkEA
@@ -1887,7 +2541,7 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                         * internal status of create operation. Under such
                         * case, nothing to be done. */
                        rc = lfsck_namespace_shrink_linkea_cond(env, com,
-                                       parent, child, ldata, cname, tfid);
+                                       parent, child, ldata, cname, &tfid);
                        if (rc >= 0) {
                                snprintf(info->lti_tmpbuf,
                                         sizeof(info->lti_tmpbuf),
@@ -1898,12 +2552,12 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                }
 
                GOTO(out, rc);
-       }
+       } /* rc == -ENOENT */
 
        if (rc != 0)
                GOTO(out, rc);
 
-       if (!lu_fid_eq(tfid, cfid)) {
+       if (!lu_fid_eq(&tfid, cfid)) {
                if (!lustre_handle_is_used(lh) && retry != NULL) {
                        *retry = true;
 
@@ -1915,7 +2569,7 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                 * may be created by the LFSCK for repairing dangling
                 * name entry. Try to replace it. */
                rc = lfsck_namespace_replace_cond(env, com, parent, child,
-                                                 tfid, cname);
+                                                 &tfid, cname);
                if (rc == 0)
                        rc = lfsck_namespace_dsd_orphan(env, com, child,
                                                        pfid, lh, type);
@@ -1923,6 +2577,19 @@ lfsck_namespace_dsd_single(const struct lu_env *env,
                GOTO(out, rc);
        }
 
+       /* Zero FID may because the remote directroy object has invalid linkEA,
+        * or lost linkEA. Under such case, the LFSCK on this MDT does not know
+        * how to repair the inconsistency, but the namespace LFSCK on the MDT
+        * where its name entry resides may has more information (name, FID) to
+        * repair such inconsistency. So here, keep the inconsistency to avoid
+        * some imporper repairing. */
+       if (fid_is_zero(pfid)) {
+               if (unknown)
+                       *unknown = true;
+
+               GOTO(out, rc = 0);
+       }
+
        /* The ".." name entry is wrong, update it. */
        if (!lu_fid_eq(pfid, lfsck_dto2fid(parent))) {
                if (!lustre_handle_is_used(lh) && retry != NULL) {
@@ -1963,6 +2630,7 @@ out:
  * \param[in,out] lh   ldlm lock handler for the given @child
  * \param[out] type    to tell the caller what the inconsistency is
  * \param[in] lpf      true if the ".." entry is under lost+found/MDTxxxx/
+ * \param[in] unknown  set if does not know how to repair the inconsistency
  *
  * \retval             positive number for repaired cases
  * \retval             0 if nothing to be repaired
@@ -1976,35 +2644,37 @@ lfsck_namespace_dsd_multiple(const struct lu_env *env,
                             struct linkea_data *ldata,
                             struct lustre_handle *lh,
                             enum lfsck_namespace_inconsistency_type *type,
-                            bool lpf)
+                            bool lpf, bool *unknown)
 {
        struct lfsck_thread_info *info          = lfsck_env_info(env);
        struct lu_name           *cname         = &info->lti_name;
        const struct lu_fid      *cfid          = lfsck_dto2fid(child);
-       struct lu_fid            *tfid          = &info->lti_fid3;
-       struct lu_fid            *pfid2         = &info->lti_fid4;
+       struct lu_fid            *pfid2         = &info->lti_fid3;
+       struct lu_fid             tfid;
        struct lfsck_namespace   *ns            = com->lc_file_ram;
        struct lfsck_instance    *lfsck         = com->lc_lfsck;
        struct lfsck_bookmark    *bk            = &lfsck->li_bookmark_ram;
        struct dt_object         *parent        = NULL;
-       struct linkea_data        ldata_new     = { 0 };
-       int                       count         = 0;
+       struct linkea_data        ldata_new     = { NULL };
+       int                       dirent_count  = 0;
        int                       rc            = 0;
        bool                      once          = true;
        ENTRY;
 
 again:
        while (ldata->ld_lee != NULL) {
-               lfsck_namespace_unpack_linkea_entry(ldata, cname, tfid,
-                                                   info->lti_key);
-               /* Drop repeated linkEA entries. */
-               lfsck_namespace_filter_linkea_entry(ldata, cname, tfid, true);
+               rc = lfsck_namespace_unpack_linkea_entry(ldata, cname, &tfid,
+                                                        info->lti_key,
+                                                        sizeof(info->lti_key));
                /* Drop invalid linkEA entry. */
-               if (!fid_is_sane(tfid)) {
-                       linkea_del_buf(ldata, cname);
+               if (rc != 0) {
+                       lfsck_linkea_del_buf(ldata, cname);
                        continue;
                }
 
+               /* Drop repeated linkEA entries. */
+               lfsck_namespace_filter_linkea_entry(ldata, cname, &tfid, true);
+
                /* If current dotdot is the .lustre/lost+found/MDTxxxx/,
                 * then it is possible that: the directry object has ever
                 * been lost, but its name entry was there. In the former
@@ -2018,12 +2688,13 @@ again:
                 * When the LFSCK runs again, if the dangling name is still
                 * there, the LFSCK should move the orphan directory object
                 * back to the normal namespace. */
-               if (!lpf && !lu_fid_eq(pfid, tfid) && once) {
+               if (!lpf && !fid_is_zero(pfid) &&
+                   !lu_fid_eq(pfid, &tfid) && once) {
                        linkea_next_entry(ldata);
                        continue;
                }
 
-               parent = lfsck_object_find_bottom(env, lfsck, tfid);
+               parent = lfsck_object_find_bottom(env, lfsck, &tfid);
                if (IS_ERR(parent))
                        RETURN(PTR_ERR(parent));
 
@@ -2034,7 +2705,7 @@ again:
                                 * there is still other chance to make the
                                 * child to be visible via other parent, then
                                 * remove this linkEA entry. */
-                               linkea_del_buf(ldata, cname);
+                               lfsck_linkea_del_buf(ldata, cname);
                                continue;
                        }
 
@@ -2044,13 +2715,12 @@ again:
                /* The linkEA entry with bad parent will be removed. */
                if (unlikely(!dt_try_as_dir(env, parent))) {
                        lfsck_object_put(env, parent);
-                       linkea_del_buf(ldata, cname);
+                       lfsck_linkea_del_buf(ldata, cname);
                        continue;
                }
 
-               rc = dt_lookup(env, parent, (struct dt_rec *)tfid,
-                              (const struct dt_key *)cname->ln_name,
-                              BYPASS_CAPA);
+               rc = dt_lookup(env, parent, (struct dt_rec *)&tfid,
+                              (const struct dt_key *)cname->ln_name);
                *pfid2 = *lfsck_dto2fid(parent);
                if (rc == -ENOENT) {
                        lfsck_object_put(env, parent);
@@ -2064,9 +2734,13 @@ again:
                        RETURN(rc);
                }
 
-               if (lu_fid_eq(tfid, cfid)) {
+               if (lu_fid_eq(&tfid, cfid)) {
                        lfsck_object_put(env, parent);
-                       if (!lu_fid_eq(pfid, pfid2)) {
+                       /* If the parent (that is declared via linkEA entry)
+                        * directory contains the specified child, but such
+                        * parent does not match the dotdot name entry, then
+                        * trust the linkEA. */
+                       if (!fid_is_zero(pfid) && !lu_fid_eq(pfid, pfid2)) {
                                *type = LNIT_UNMATCHED_PAIRS;
                                rc = lfsck_namespace_repair_unmatched_pairs(env,
                                                com, child, pfid2, cname);
@@ -2078,11 +2752,8 @@ rebuild:
                        /* It is the most common case that we find the
                         * name entry corresponding to the linkEA entry
                         * that matches the ".." name entry. */
-                       rc = linkea_data_new(&ldata_new, &info->lti_big_buf);
-                       if (rc != 0)
-                               RETURN(rc);
-
-                       rc = linkea_add_buf(&ldata_new, cname, pfid2);
+                       rc = linkea_links_new(&ldata_new, &info->lti_big_buf,
+                                             cname, pfid2);
                        if (rc != 0)
                                RETURN(rc);
 
@@ -2091,18 +2762,19 @@ rebuild:
                        if (rc < 0)
                                RETURN(rc);
 
-                       linkea_del_buf(ldata, cname);
+                       lfsck_linkea_del_buf(ldata, cname);
                        linkea_first_entry(ldata);
                        /* There may be some invalid dangling name entries under
                         * other parent directories, remove all of them. */
                        while (ldata->ld_lee != NULL) {
-                               lfsck_namespace_unpack_linkea_entry(ldata,
-                                               cname, tfid, info->lti_key);
-                               if (!fid_is_sane(tfid))
+                               rc = lfsck_namespace_unpack_linkea_entry(ldata,
+                                               cname, &tfid, info->lti_key,
+                                               sizeof(info->lti_key));
+                               if (rc != 0)
                                        goto next;
 
                                parent = lfsck_object_find_bottom(env, lfsck,
-                                                                 tfid);
+                                                                 &tfid);
                                if (IS_ERR(parent)) {
                                        rc = PTR_ERR(parent);
                                        if (rc != -ENOENT &&
@@ -2128,23 +2800,23 @@ rebuild:
                                        goto next;
                                }
 
-                               count += rc;
+                               dirent_count += rc;
 
 next:
-                               linkea_del_buf(ldata, cname);
+                               lfsck_linkea_del_buf(ldata, cname);
                        }
 
-                       ns->ln_dirent_repaired += count;
+                       ns->ln_dirent_repaired += dirent_count;
 
                        RETURN(rc);
-               }
+               } /* lu_fid_eq(&tfid, lfsck_dto2fid(child)) */
 
                lfsck_ibits_unlock(lh, LCK_EX);
                /* The name entry references another MDT-object that may be
                 * created by the LFSCK for repairing dangling name entry.
                 * Try to replace it. */
                rc = lfsck_namespace_replace_cond(env, com, parent, child,
-                                                 tfid, cname);
+                                                 &tfid, cname);
                lfsck_object_put(env, parent);
                if (rc < 0)
                        RETURN(rc);
@@ -2152,12 +2824,17 @@ next:
                if (rc > 0)
                        goto rebuild;
 
-               linkea_del_buf(ldata, cname);
-       }
+               lfsck_linkea_del_buf(ldata, cname);
+       } /* while (ldata->ld_lee != NULL) */
 
+       /* If there is still linkEA overflow, return. */
+       if (unlikely(ldata->ld_leh->leh_overflow_time))
+               RETURN(0);
+
+       linkea_first_entry(ldata);
        if (ldata->ld_leh->leh_reccount == 1) {
                rc = lfsck_namespace_dsd_single(env, com, child, pfid, ldata,
-                                               lh, type, NULL);
+                                               lh, type, NULL, unknown);
 
                RETURN(rc);
        }
@@ -2171,7 +2848,6 @@ next:
                RETURN(rc);
        }
 
-       linkea_first_entry(ldata);
        /* If the dangling name entry for the orphan directory object has
         * been remvoed, then just check whether the directory object is
         * still under the .lustre/lost+found/MDTxxxx/ or not. */
@@ -2192,26 +2868,134 @@ next:
 }
 
 /**
- * Double scan the directory object for namespace LFSCK.
- *
- * This function will verify the <parent, child> pairs in the namespace tree:
- * the parent references the child via some name entry that should be in the
- * child's linkEA entry, the child should back references the parent via its
- * ".." name entry.
+ * Repair the object's nlink attribute.
  *
- * The LFSCK will scan every linkEA entry in turn until find out the first
- * matched pairs. If found, then all other linkEA entries will be dropped.
- * If all the linkEA entries cannot match the ".." name entry, then there
- * are serveral possible cases:
+ * If all the known name entries have been verified, then the object's hard
+ * link attribute should match the object's linkEA entries count unless the
+ * object's has too many hard link to be recorded in the linkEA. Such cases
+ * should have been marked in the LFSCK trace file. Otherwise, trust the
+ * linkEA to update the object's nlink attribute.
  *
- * 1) If there is only one linkEA entry, then trust it as long as the PFID
- *    in the linkEA entry is valid.
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] obj      pointer to the dt_object to be handled
+ * \param[in,out] la   pointer to buffer to object's attribute before
+ *                     and after the repairing
  *
- * 2) If there are multiple linkEA entries, then try to find the linkEA
- *    that matches the ".." name entry. If found, then all other entries
- *    are invalid; otherwise, it is quite possible that the ".." name entry
- *    is corrupted. Under such case, the LFSCK will rebuild the ".." name
- *    entry according to the first valid linkEA entry (both the parent and
+ * \retval             positive number for repaired cases
+ * \retval             0 if nothing to be repaired
+ * \retval             negative error number on failure
+ */
+static int lfsck_namespace_repair_nlink(const struct lu_env *env,
+                                       struct lfsck_component *com,
+                                       struct dt_object *obj,
+                                       struct lu_attr *la)
+{
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct dt_device                *dev    = lfsck_obj2dev(obj);
+       const struct lu_fid             *cfid   = lfsck_dto2fid(obj);
+       struct thandle                  *th     = NULL;
+       struct linkea_data               ldata  = { NULL };
+       struct lustre_handle             lh     = { 0 };
+       __u32                            old    = la->la_nlink;
+       int                              rc     = 0;
+       ENTRY;
+
+       LASSERT(!dt_object_remote(obj));
+
+       rc = lfsck_ibits_lock(env, lfsck, obj, &lh,
+                             MDS_INODELOCK_UPDATE, LCK_PW);
+       if (rc != 0)
+               GOTO(log, rc);
+
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(log, rc = PTR_ERR(th));
+
+       la->la_valid = LA_NLINK;
+       rc = dt_declare_attr_set(env, obj, la, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       dt_write_lock(env, obj, 0);
+       /* If the LFSCK is marked as LF_INCOMPLETE, then means some MDT has
+        * ever tried to verify some remote MDT-object that resides on this
+        * MDT, but this MDT failed to respond such request. So means there
+        * may be some remote name entry on other MDT that references this
+        * object with another name, so we cannot know whether this linkEA
+        * is valid or not. So keep it there and maybe resolved when next
+        * LFSCK run. */
+       if (ns->ln_flags & LF_INCOMPLETE)
+               GOTO(unlock, rc = 0);
+
+       rc = dt_attr_get(env, obj, la);
+       if (rc != 0)
+               GOTO(unlock, rc = (rc == -ENOENT ? 0 : rc));
+
+       rc = lfsck_links_read2_with_rec(env, obj, &ldata);
+       if (rc)
+               GOTO(unlock, rc = (rc == -ENODATA ? 0 : rc));
+
+       /* XXX: Currently, we only update the nlink attribute if the known
+        *      linkEA entries is larger than the nlink attribute. That is
+        *      safe action. */
+       if (la->la_nlink >= ldata.ld_leh->leh_reccount ||
+           unlikely(la->la_nlink == 0 ||
+                    ldata.ld_leh->leh_overflow_time))
+               GOTO(unlock, rc = 0);
+
+       la->la_nlink = ldata.ld_leh->leh_reccount;
+       if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
+               GOTO(unlock, rc = 1);
+
+       rc = dt_attr_set(env, obj, la, th);
+
+       GOTO(unlock, rc = (rc == 0 ? 1 : rc));
+
+unlock:
+       dt_write_unlock(env, obj);
+
+stop:
+       dt_trans_stop(env, dev, th);
+
+log:
+       lfsck_ibits_unlock(&lh, LCK_PW);
+       CDEBUG(D_LFSCK, "%s: namespace LFSCK repaired the object "DFID"'s "
+              "nlink count from %u to %u: rc = %d\n",
+              lfsck_lfsck2name(lfsck), PFID(cfid), old, la->la_nlink, rc);
+
+       if (rc != 0)
+               ns->ln_flags |= LF_INCONSISTENT;
+
+       return rc;
+}
+
+/**
+ * Double scan the directory object for namespace LFSCK.
+ *
+ * This function will verify the <parent, child> pairs in the namespace tree:
+ * the parent references the child via some name entry that should be in the
+ * child's linkEA entry, the child should back references the parent via its
+ * ".." name entry.
+ *
+ * The LFSCK will scan every linkEA entry in turn until find out the first
+ * matched pairs. If found, then all other linkEA entries will be dropped.
+ * If all the linkEA entries cannot match the ".." name entry, then there
+ * are serveral possible cases:
+ *
+ * 1) If there is only one linkEA entry, then trust it as long as the PFID
+ *    in the linkEA entry is valid.
+ *
+ * 2) If there are multiple linkEA entries, then try to find the linkEA
+ *    that matches the ".." name entry. If found, then all other entries
+ *    are invalid; otherwise, it is quite possible that the ".." name entry
+ *    is corrupted. Under such case, the LFSCK will rebuild the ".." name
+ *    entry according to the first valid linkEA entry (both the parent and
  *    the name entry should exist).
  *
  * 3) If the directory object has no (valid) linkEA entry, then the
@@ -2238,7 +3022,7 @@ static int lfsck_namespace_double_scan_dir(const struct lu_env *env,
        struct lfsck_namespace   *ns            = com->lc_file_ram;
        struct lfsck_instance    *lfsck         = com->lc_lfsck;
        struct lustre_handle      lh            = { 0 };
-       struct linkea_data        ldata         = { 0 };
+       struct linkea_data        ldata         = { NULL };
        bool                      unknown       = false;
        bool                      lpf           = false;
        bool                      retry         = false;
@@ -2248,7 +3032,24 @@ static int lfsck_namespace_double_scan_dir(const struct lu_env *env,
 
        LASSERT(!dt_object_remote(child));
 
-       if (!(lfsck->li_bookmark_ram.lb_param & LPF_ALL_TGT)) {
+       if (flags & LNTF_UNCERTAIN_LMV) {
+               if (flags & LNTF_RECHECK_NAME_HASH) {
+                       rc = lfsck_namespace_scan_shard(env, com, child);
+                       if (rc < 0)
+                               RETURN(rc);
+
+                       ns->ln_striped_shards_scanned++;
+               } else {
+                       ns->ln_striped_shards_skipped++;
+               }
+       }
+
+       flags &= ~(LNTF_RECHECK_NAME_HASH | LNTF_UNCERTAIN_LMV);
+       if (flags == 0)
+               RETURN(0);
+
+       if (flags & (LNTF_CHECK_LINKEA | LNTF_CHECK_PARENT) &&
+           !(lfsck->li_bookmark_ram.lb_param & LPF_ALL_TGT)) {
                CDEBUG(D_LFSCK, "%s: some MDT(s) maybe NOT take part in the"
                       "the namespace LFSCK, then the LFSCK cannot guarantee"
                       "all the name entries have been verified in first-stage"
@@ -2282,7 +3083,7 @@ lock:
        }
 
        rc = dt_lookup(env, child, (struct dt_rec *)pfid,
-                      (const struct dt_key *)dotdot, BYPASS_CAPA);
+                      (const struct dt_key *)dotdot);
        if (rc != 0) {
                if (rc != -ENOENT && rc != -ENODATA && rc != -EINVAL) {
                        dt_read_unlock(env, child);
@@ -2299,6 +3100,8 @@ lock:
        } else if (lfsck->li_lpf_obj != NULL &&
                   lu_fid_eq(pfid, lfsck_dto2fid(lfsck->li_lpf_obj))) {
                lpf = true;
+       } else if (unlikely(!fid_is_sane(pfid))) {
+               fid_zero(pfid);
        }
 
        rc = lfsck_links_read(env, child, &ldata);
@@ -2333,6 +3136,20 @@ lock:
                         *    directory, then handle it as orphan. */
                        lfsck_ibits_unlock(&lh, LCK_EX);
                        type = LNIT_MUL_REF;
+
+                       /* If the LFSCK is marked as LF_INCOMPLETE,
+                        * then means some MDT has ever tried to
+                        * verify some remote MDT-object that resides
+                        * on this MDT, but this MDT failed to respond
+                        * such request. So means there may be some
+                        * remote name entry on other MDT that
+                        * references this object with another name,
+                        * so we cannot know whether this linkEA is
+                        * valid or not. So keep it there and maybe
+                        * resolved when next LFSCK run. */
+                       if (ns->ln_flags & LF_INCOMPLETE)
+                               GOTO(out, rc = 0);
+
                        snprintf(info->lti_tmpbuf, sizeof(info->lti_tmpbuf),
                                 "-"DFID, PFID(pfid));
                        rc = lfsck_namespace_insert_orphan(env, com, child,
@@ -2340,13 +3157,13 @@ lock:
                }
 
                GOTO(out, rc);
-       }
+       } /* rc != 0 */
 
        linkea_first_entry(&ldata);
        /* This is the most common case: the object has unique linkEA entry. */
        if (ldata.ld_leh->leh_reccount == 1) {
                rc = lfsck_namespace_dsd_single(env, com, child, pfid, &ldata,
-                                               &lh, &type, &retry);
+                                               &lh, &type, &retry, &unknown);
                if (retry) {
                        LASSERT(!lustre_handle_is_used(&lh));
 
@@ -2378,7 +3195,7 @@ lock:
         *    but the LFSCK cannot aware that at that time, then it adds
         *    the bad linkEA entry for further processing. */
        rc = lfsck_namespace_dsd_multiple(env, com, child, pfid, &ldata,
-                                         &lh, &type, lpf);
+                                         &lh, &type, lpf, &unknown);
 
        GOTO(out, rc);
 
@@ -2406,6 +3223,117 @@ out:
        return rc;
 }
 
+#define lfsck_time_before(a, b)                \
+       (typecheck(__u32, a) &&         \
+        typecheck(__u32, b) &&         \
+        ((int)(a) - (int)(b) < 0))
+
+static inline bool
+lfsck_namespace_linkea_stale_overflow(struct linkea_data *ldata,
+                                     struct lfsck_namespace *ns)
+{
+       /* Both the leh_overflow_time and ln_time_latest_reset are
+        * local time based, so need NOT to care about clock drift
+        * among the servers. */
+       return ldata->ld_leh->leh_overflow_time &&
+              lfsck_time_before(ldata->ld_leh->leh_overflow_time,
+                                ns->ln_time_latest_reset);
+}
+
+/**
+ * Clear the object's linkEA overflow timestamp.
+ *
+ * If the MDT-object has too many hard links as to the linkEA cannot hold
+ * all of them, then overflow timestamp will be set in the linkEA header.
+ * If some hard links are removed after that, then it is possible to hold
+ * other missed linkEA entries. If the namespace LFSCK have added all the
+ * related linkEA entries, then it will remove the overflow timestamp.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] ldata    pointer to the linkEA data for the given @obj
+ * \param[in] obj      pointer to the dt_object to be handled
+ *
+ * \retval             positive number for repaired cases
+ * \retval             0 if nothing to be repaired
+ * \retval             negative error number on failure
+ */
+static int lfsck_namespace_linkea_clear_overflow(const struct lu_env *env,
+                                                struct lfsck_component *com,
+                                                struct linkea_data *ldata,
+                                                struct dt_object *obj)
+{
+       struct lfsck_namespace *ns = com->lc_file_ram;
+       struct lfsck_instance *lfsck = com->lc_lfsck;
+       struct dt_device *dev = lfsck_obj2dev(obj);
+       struct thandle *th = NULL;
+       struct lustre_handle lh = { 0 };
+       struct lu_buf linkea_buf;
+       int rc = 0;
+       ENTRY;
+
+       LASSERT(!dt_object_remote(obj));
+
+       rc = lfsck_ibits_lock(env, lfsck, obj, &lh,
+                             MDS_INODELOCK_UPDATE, LCK_PW);
+       if (rc != 0)
+               GOTO(log, rc);
+
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(log, rc = PTR_ERR(th));
+
+       rc = dt_declare_xattr_set(env, obj,
+                       lfsck_buf_get_const(env, NULL, MAX_LINKEA_SIZE),
+                       XATTR_NAME_LINK, 0, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       dt_write_lock(env, obj, 0);
+       rc = lfsck_links_read(env, obj, ldata);
+       if (rc != 0)
+               GOTO(unlock, rc);
+
+       if (unlikely(!lfsck_namespace_linkea_stale_overflow(ldata, ns)))
+               GOTO(unlock, rc = 0);
+
+       ldata->ld_leh->leh_overflow_time = 0;
+       if (lfsck->li_bookmark_ram.lb_param & LPF_DRYRUN)
+               GOTO(unlock, rc = 1);
+
+       /* If all known entries are in the linkEA, then the 'leh_reccount'
+        * should NOT be zero. */
+       LASSERT(ldata->ld_leh->leh_reccount > 0);
+
+       lfsck_buf_init(&linkea_buf, ldata->ld_buf->lb_buf,
+                      ldata->ld_leh->leh_len);
+       rc = dt_xattr_set(env, obj, &linkea_buf, XATTR_NAME_LINK, 0, th);
+       if (unlikely(rc == -ENOSPC))
+               rc = 0;
+       else if (!rc)
+               rc = 1;
+
+       GOTO(unlock, rc);
+
+unlock:
+       dt_write_unlock(env, obj);
+
+stop:
+       dt_trans_stop(env, dev, th);
+
+log:
+       lfsck_ibits_unlock(&lh, LCK_PW);
+       CDEBUG(D_LFSCK, "%s: clear linkea overflow timestamp for the object "
+              DFID": rc = %d\n",
+              lfsck_lfsck2name(lfsck), PFID(lfsck_dto2fid(obj)), rc);
+
+       return rc;
+}
+
 /**
  * Double scan the MDT-object for namespace LFSCK.
  *
@@ -2437,7 +3365,7 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
        struct lfsck_instance    *lfsck    = com->lc_lfsck;
        struct lfsck_namespace   *ns       = com->lc_file_ram;
        struct dt_object         *parent   = NULL;
-       struct linkea_data        ldata    = { 0 };
+       struct linkea_data        ldata    = { NULL };
        bool                      repaired = false;
        int                       count    = 0;
        int                       rc;
@@ -2459,13 +3387,53 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
 
        rc = lfsck_links_read(env, child, &ldata);
        dt_read_unlock(env, child);
+
+       if (rc == -EINVAL) {
+               struct lustre_handle lh = { 0 };
+
+               rc = lfsck_ibits_lock(env, com->lc_lfsck, child, &lh,
+                                     MDS_INODELOCK_UPDATE |
+                                     MDS_INODELOCK_XATTR, LCK_EX);
+               if (rc == 0) {
+                       rc = lfsck_namespace_links_remove(env, com, child);
+                       lfsck_ibits_unlock(&lh, LCK_EX);
+               }
+
+               GOTO(out, rc);
+       }
+
        if (rc != 0)
                GOTO(out, rc);
 
+       if (!(ns->ln_flags & LF_INCOMPLETE) &&
+           unlikely(lfsck_namespace_linkea_stale_overflow(&ldata, ns))) {
+               rc = lfsck_namespace_linkea_clear_overflow(env, com, &ldata,
+                                                          child);
+               if (rc < 0)
+                       GOTO(out, rc);
+
+               if (rc > 0)
+                       ns->ln_linkea_overflow_cleared++;
+       }
+
        linkea_first_entry(&ldata);
        while (ldata.ld_lee != NULL) {
-               lfsck_namespace_unpack_linkea_entry(&ldata, cname, pfid,
-                                                   info->lti_key);
+               rc = lfsck_namespace_unpack_linkea_entry(&ldata, cname, pfid,
+                                                        info->lti_key,
+                                                        sizeof(info->lti_key));
+               /* Invalid PFID in the linkEA entry. */
+               if (rc != 0) {
+                       rc = lfsck_namespace_shrink_linkea(env, com, child,
+                                               &ldata, cname, pfid, true);
+                       if (rc < 0)
+                               GOTO(out, rc);
+
+                       if (rc > 0)
+                               repaired = true;
+
+                       continue;
+               }
+
                rc = lfsck_namespace_filter_linkea_entry(&ldata, cname, pfid,
                                                         false);
                /* Found repeated linkEA entries */
@@ -2483,24 +3451,13 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
                        /* fall through */
                }
 
-               /* Invalid PFID in the linkEA entry. */
-               if (!fid_is_sane(pfid)) {
-                       rc = lfsck_namespace_shrink_linkea(env, com, child,
-                                               &ldata, cname, pfid, true);
-                       if (rc < 0)
-                               GOTO(out, rc);
-
-                       if (rc > 0)
-                               repaired = true;
-
-                       continue;
-               }
-
                parent = lfsck_object_find_bottom(env, lfsck, pfid);
                if (IS_ERR(parent))
                        GOTO(out, rc = PTR_ERR(parent));
 
                if (!dt_object_exists(parent)) {
+
+lost_parent:
                        if (ldata.ld_leh->leh_reccount > 1) {
                                /* If it is NOT the last linkEA entry, then
                                 * there is still other chance to make the
@@ -2509,9 +3466,25 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
                                rc = lfsck_namespace_shrink_linkea(env, com,
                                        child, &ldata, cname, pfid, true);
                        } else {
+                               /* If the LFSCK is marked as LF_INCOMPLETE,
+                                * then means some MDT has ever tried to
+                                * verify some remote MDT-object that resides
+                                * on this MDT, but this MDT failed to respond
+                                * such request. So means there may be some
+                                * remote name entry on other MDT that
+                                * references this object with another name,
+                                * so we cannot know whether this linkEA is
+                                * valid or not. So keep it there and maybe
+                                * resolved when next LFSCK run. */
+                               if (ns->ln_flags & LF_INCOMPLETE) {
+                                       lfsck_object_put(env, parent);
+
+                                       GOTO(out, rc = 0);
+                               }
+
                                /* Create the lost parent as an orphan. */
-                               rc = lfsck_namespace_create_orphan(env, com,
-                                                                  parent);
+                               rc = lfsck_namespace_create_orphan_dir(env, com,
+                                                               parent, NULL);
                                if (rc < 0) {
                                        lfsck_object_put(env, parent);
 
@@ -2548,7 +3521,7 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
                                repaired = true;
 
                        continue;
-               }
+               } /* !dt_object_exists(parent) */
 
                /* The linkEA entry with bad parent will be removed. */
                if (unlikely(!dt_try_as_dir(env, parent))) {
@@ -2565,8 +3538,7 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
                }
 
                rc = dt_lookup(env, parent, (struct dt_rec *)cfid,
-                              (const struct dt_key *)cname->ln_name,
-                              BYPASS_CAPA);
+                              (const struct dt_key *)cname->ln_name);
                if (rc != 0 && rc != -ENOENT) {
                        lfsck_object_put(env, parent);
 
@@ -2609,12 +3581,14 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
                        continue;
                }
 
-               rc = dt_attr_get(env, child, la, BYPASS_CAPA);
+               /* The following handles -ENOENT case */
+
+               rc = dt_attr_get(env, child, la);
                if (rc != 0)
                        GOTO(out, rc);
 
                /* If there is no name entry in the parent dir and the object
-                * link count is less than the linkea entries count, then the
+                * link count is fewer than the linkea entries count, then the
                 * linkea entry should be removed. */
                if (ldata.ld_leh->leh_reccount > la->la_nlink) {
                        rc = lfsck_namespace_shrink_linkea_cond(env, com,
@@ -2629,9 +3603,51 @@ static int lfsck_namespace_double_scan_one(const struct lu_env *env,
                        continue;
                }
 
+               /* If the LFSCK is marked as LF_INCOMPLETE, then means some
+                * MDT has ever tried to verify some remote MDT-object that
+                * resides on this MDT, but this MDT failed to respond such
+                * request. So means there may be some remote name entry on
+                * other MDT that references this object with another name,
+                * so we cannot know whether this linkEA is valid or not.
+                * So keep it there and maybe resolved when next LFSCK run. */
+               if (ns->ln_flags & LF_INCOMPLETE) {
+                       lfsck_object_put(env, parent);
+
+                       GOTO(out, rc = 0);
+               }
+
+               rc = lfsck_namespace_check_name(env, parent, child, cname);
+               if (rc == -ENOENT)
+                       goto lost_parent;
+
+               if (rc < 0) {
+                       lfsck_object_put(env, parent);
+
+                       GOTO(out, rc);
+               }
+
+               /* It is an invalid name entry, drop it. */
+               if (unlikely(rc > 0)) {
+                       lfsck_object_put(env, parent);
+                       rc = lfsck_namespace_shrink_linkea(env, com, child,
+                                               &ldata, cname, pfid, true);
+                       if (rc < 0)
+                               GOTO(out, rc);
+
+                       if (rc > 0)
+                               repaired = true;
+
+                       continue;
+               }
+
                /* Add the missing name entry back to the namespace. */
                rc = lfsck_namespace_insert_normal(env, com, parent, child,
                                                   cname->ln_name);
+               if (unlikely(rc == -ESTALE))
+                       /* It may happen when the remote object has been
+                        * removed, but the local MDT is not aware of that. */
+                       goto lost_parent;
+
                if (unlikely(rc == -EEXIST))
                        /* Unfortunately, someone reused the name under the
                         * parent by race. So we have to remove the linkEA
@@ -2662,33 +3678,58 @@ out:
        if (rc < 0 && rc != -ENODATA)
                return rc;
 
-       if (rc == 0) {
-               LASSERT(ldata.ld_leh != NULL);
-
+       if (rc == 0 && ldata.ld_leh != NULL)
                count = ldata.ld_leh->leh_reccount;
-       }
 
        if (count == 0) {
-               /* If the child becomes orphan, then insert it into
-                * the global .lustre/lost+found/MDTxxxx directory. */
-               rc = lfsck_namespace_insert_orphan(env, com, child, "", "O",
-                                                  &count);
-               if (rc < 0)
-                       return rc;
+               /* If the LFSCK is marked as LF_INCOMPLETE, then means some
+                * MDT has ever tried to verify some remote MDT-object that
+                * resides on this MDT, but this MDT failed to respond such
+                * request. So means there may be some remote name entry on
+                * other MDT that references this object with another name,
+                * so we cannot know whether this linkEA is valid or not.
+                * So keep it there and maybe resolved when next LFSCK run. */
+               if (!(ns->ln_flags & LF_INCOMPLETE) &&
+                   (ldata.ld_leh == NULL ||
+                    !ldata.ld_leh->leh_overflow_time)) {
+                       /* If the child becomes orphan, then insert it into
+                        * the global .lustre/lost+found/MDTxxxx directory. */
+                       rc = lfsck_namespace_insert_orphan(env, com, child,
+                                                          "", "O", &count);
+                       if (rc < 0)
+                               return rc;
 
-               if (rc > 0) {
-                       ns->ln_mul_ref_repaired++;
-                       repaired = true;
+                       if (rc > 0) {
+                               ns->ln_mul_ref_repaired++;
+                               repaired = true;
+                       }
                }
-       }
-
-       rc = dt_attr_get(env, child, la, BYPASS_CAPA);
-       if (rc != 0)
-               return rc;
+       } else {
+               rc = dt_attr_get(env, child, la);
+               if (rc != 0)
+                       return rc;
 
-       if (la->la_nlink != count) {
-               /* XXX: there will be other patch(es) for MDT-object
-                *      hard links verification. */
+               if (la->la_nlink != 0 && la->la_nlink != count) {
+                       if (unlikely(!S_ISREG(lfsck_object_type(child)) &&
+                                    !S_ISLNK(lfsck_object_type(child)))) {
+                               CDEBUG(D_LFSCK, "%s: namespace LFSCK finds "
+                                      "the object "DFID"'s nlink count %d "
+                                      "does not match linkEA count %d, "
+                                      "type %o, skip it.\n",
+                                      lfsck_lfsck2name(lfsck),
+                                      PFID(lfsck_dto2fid(child)),
+                                      la->la_nlink, count,
+                                      lfsck_object_type(child));
+                       } else if (la->la_nlink < count &&
+                                  likely(!ldata.ld_leh->leh_overflow_time)) {
+                               rc = lfsck_namespace_repair_nlink(env, com,
+                                                                 child, la);
+                               if (rc > 0) {
+                                       ns->ln_objs_nlink_repaired++;
+                                       rc = 0;
+                               }
+                       }
+               }
        }
 
        if (repaired) {
@@ -2709,60 +3750,140 @@ static void lfsck_namespace_dump_statistics(struct seq_file *m,
                                            __u32 time_phase1,
                                            __u32 time_phase2)
 {
-       seq_printf(m, "checked_phase1: "LPU64"\n"
-                     "checked_phase2: "LPU64"\n"
-                     "updated_phase1: "LPU64"\n"
-                     "updated_phase2: "LPU64"\n"
-                     "failed_phase1: "LPU64"\n"
-                     "failed_phase2: "LPU64"\n"
-                     "directories: "LPU64"\n"
-                     "dirent_repaired: "LPU64"\n"
-                     "linkea_repaired: "LPU64"\n"
-                     "nlinks_repaired: "LPU64"\n"
-                     "multiple_linked_checked: "LPU64"\n"
-                     "multiple_linked_repaired: "LPU64"\n"
-                     "unknown_inconsistency: "LPU64"\n"
-                     "unmatched_pairs_repaired: "LPU64"\n"
-                     "dangling_repaired: "LPU64"\n"
-                     "multiple_referenced_repaired: "LPU64"\n"
-                     "bad_file_type_repaired: "LPU64"\n"
-                     "lost_dirent_repaired: "LPU64"\n"
-                     "success_count: %u\n"
-                     "run_time_phase1: %u seconds\n"
-                     "run_time_phase2: %u seconds\n",
-                     checked_phase1,
-                     checked_phase2,
-                     ns->ln_items_repaired,
-                     ns->ln_objs_repaired_phase2,
-                     ns->ln_items_failed,
-                     ns->ln_objs_failed_phase2,
-                     ns->ln_dirs_checked,
-                     ns->ln_dirent_repaired,
-                     ns->ln_linkea_repaired,
-                     ns->ln_objs_nlink_repaired,
-                     ns->ln_mul_linked_checked,
-                     ns->ln_mul_linked_repaired,
-                     ns->ln_unknown_inconsistency,
-                     ns->ln_unmatched_pairs_repaired,
-                     ns->ln_dangling_repaired,
-                     ns->ln_mul_ref_repaired,
-                     ns->ln_bad_type_repaired,
-                     ns->ln_lost_dirent_repaired,
-                     ns->ln_success_count,
-                     time_phase1,
-                     time_phase2);
+       seq_printf(m, "checked_phase1: %llu\n"
+                  "checked_phase2: %llu\n"
+                  "updated_phase1: %llu\n"
+                  "updated_phase2: %llu\n"
+                  "failed_phase1: %llu\n"
+                  "failed_phase2: %llu\n"
+                  "directories: %llu\n"
+                  "dirent_repaired: %llu\n"
+                  "linkea_repaired: %llu\n"
+                  "nlinks_repaired: %llu\n"
+                  "multiple_linked_checked: %llu\n"
+                  "multiple_linked_repaired: %llu\n"
+                  "unknown_inconsistency: %llu\n"
+                  "unmatched_pairs_repaired: %llu\n"
+                  "dangling_repaired: %llu\n"
+                  "multiple_referenced_repaired: %llu\n"
+                  "bad_file_type_repaired: %llu\n"
+                  "lost_dirent_repaired: %llu\n"
+                  "local_lost_found_scanned: %llu\n"
+                  "local_lost_found_moved: %llu\n"
+                  "local_lost_found_skipped: %llu\n"
+                  "local_lost_found_failed: %llu\n"
+                  "striped_dirs_scanned: %llu\n"
+                  "striped_dirs_repaired: %llu\n"
+                  "striped_dirs_failed: %llu\n"
+                  "striped_dirs_disabled: %llu\n"
+                  "striped_dirs_skipped: %llu\n"
+                  "striped_shards_scanned: %llu\n"
+                  "striped_shards_repaired: %llu\n"
+                  "striped_shards_failed: %llu\n"
+                  "striped_shards_skipped: %llu\n"
+                  "name_hash_repaired: %llu\n"
+                  "linkea_overflow_cleared: %llu\n"
+                  "success_count: %u\n"
+                  "run_time_phase1: %u seconds\n"
+                  "run_time_phase2: %u seconds\n",
+                  checked_phase1,
+                  checked_phase2,
+                  ns->ln_items_repaired,
+                  ns->ln_objs_repaired_phase2,
+                  ns->ln_items_failed,
+                  ns->ln_objs_failed_phase2,
+                  ns->ln_dirs_checked,
+                  ns->ln_dirent_repaired,
+                  ns->ln_linkea_repaired,
+                  ns->ln_objs_nlink_repaired,
+                  ns->ln_mul_linked_checked,
+                  ns->ln_mul_linked_repaired,
+                  ns->ln_unknown_inconsistency,
+                  ns->ln_unmatched_pairs_repaired,
+                  ns->ln_dangling_repaired,
+                  ns->ln_mul_ref_repaired,
+                  ns->ln_bad_type_repaired,
+                  ns->ln_lost_dirent_repaired,
+                  ns->ln_local_lpf_scanned,
+                  ns->ln_local_lpf_moved,
+                  ns->ln_local_lpf_skipped,
+                  ns->ln_local_lpf_failed,
+                  ns->ln_striped_dirs_scanned,
+                  ns->ln_striped_dirs_repaired,
+                  ns->ln_striped_dirs_failed,
+                  ns->ln_striped_dirs_disabled,
+                  ns->ln_striped_dirs_skipped,
+                  ns->ln_striped_shards_scanned,
+                  ns->ln_striped_shards_repaired,
+                  ns->ln_striped_shards_failed,
+                  ns->ln_striped_shards_skipped,
+                  ns->ln_name_hash_repaired,
+                  ns->ln_linkea_overflow_cleared,
+                  ns->ln_success_count,
+                  time_phase1,
+                  time_phase2);
 }
 
-/* namespace APIs */
-
+static void lfsck_namespace_release_lmv(const struct lu_env *env,
+                                       struct lfsck_component *com)
+{
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+
+       while (!list_empty(&lfsck->li_list_lmv)) {
+               struct lfsck_lmv_unit   *llu;
+               struct lfsck_lmv        *llmv;
+
+               llu = list_entry(lfsck->li_list_lmv.next,
+                                struct lfsck_lmv_unit, llu_link);
+               llmv = &llu->llu_lmv;
+
+               LASSERTF(atomic_read(&llmv->ll_ref) == 1,
+                        "still in using: %u\n",
+                        atomic_read(&llmv->ll_ref));
+
+               ns->ln_striped_dirs_skipped++;
+               lfsck_lmv_put(env, llmv);
+       }
+}
+
+static int lfsck_namespace_check_for_double_scan(const struct lu_env *env,
+                                                struct lfsck_component *com,
+                                                struct dt_object *obj)
+{
+       struct lu_attr *la = &lfsck_env_info(env)->lti_la;
+       int             rc;
+
+       rc = dt_attr_get(env, obj, la);
+       if (rc != 0)
+               return rc;
+
+       /* zero-linkEA object may be orphan, but it also maybe because
+        * of upgrading. Currently, we cannot record it for double scan.
+        * Because it may cause the LFSCK trace file to be too large. */
+
+       /* "la_ctime" == 1 means that it has ever been removed from
+        * backend /lost+found directory but not been added back to
+        * the normal namespace yet. */
+
+       if ((S_ISREG(lfsck_object_type(obj)) && la->la_nlink > 1) ||
+           unlikely(la->la_ctime == 1))
+               rc = lfsck_namespace_trace_update(env, com, lfsck_dto2fid(obj),
+                                                 LNTF_CHECK_LINKEA, true);
+
+       return rc;
+}
+
+/* namespace APIs */
+
 static int lfsck_namespace_reset(const struct lu_env *env,
                                 struct lfsck_component *com, bool init)
 {
-       struct lfsck_instance   *lfsck = com->lc_lfsck;
-       struct lfsck_namespace  *ns    = com->lc_file_ram;
-       struct dt_object        *root;
-       struct dt_object        *dto;
-       int                      rc;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct dt_object                *root;
+       int                              rc;
        ENTRY;
 
        root = dt_locate(env, lfsck->li_bottom, &lfsck->li_local_root_fid);
@@ -2785,27 +3906,23 @@ static int lfsck_namespace_reset(const struct lu_env *env,
        }
        ns->ln_magic = LFSCK_NAMESPACE_MAGIC;
        ns->ln_status = LS_INIT;
+       ns->ln_time_latest_reset = cfs_time_current_sec();
 
-       rc = local_object_unlink(env, lfsck->li_bottom, root,
-                                lfsck_namespace_name);
-       if (rc != 0)
+       rc = lfsck_load_one_trace_file(env, com, root, &com->lc_obj,
+                                      &dt_lfsck_namespace_features,
+                                      LFSCK_NAMESPACE, true);
+       if (rc)
                GOTO(out, rc);
 
-       lfsck_object_put(env, com->lc_obj);
-       com->lc_obj = NULL;
-       dto = local_index_find_or_create(env, lfsck->li_los, root,
-                                        lfsck_namespace_name,
-                                        S_IFREG | S_IRUGO | S_IWUSR,
-                                        &dt_lfsck_features);
-       if (IS_ERR(dto))
-               GOTO(out, rc = PTR_ERR(dto));
-
-       com->lc_obj = dto;
-       rc = dto->do_ops->do_index_try(env, dto, &dt_lfsck_features);
+       rc = lfsck_load_sub_trace_files(env, com, &dt_lfsck_namespace_features,
+                                       LFSCK_NAMESPACE, true);
        if (rc != 0)
                GOTO(out, rc);
 
-       rc = lfsck_namespace_store(env, com, true);
+       lad->lad_incomplete = 0;
+       CFS_RESET_BITMAP(lad->lad_bitmap);
+
+       rc = lfsck_namespace_store(env, com);
 
        GOTO(out, rc);
 
@@ -2813,7 +3930,7 @@ out:
        up_write(&com->lc_sem);
 
 put:
-       lu_object_put(env, &root->do_lu);
+       lfsck_object_put(env, root);
 log:
        CDEBUG(D_LFSCK, "%s: namespace LFSCK reset: rc = %d\n",
               lfsck_lfsck2name(lfsck), rc);
@@ -2833,6 +3950,98 @@ lfsck_namespace_fail(const struct lu_env *env, struct lfsck_component *com,
        up_write(&com->lc_sem);
 }
 
+static void lfsck_namespace_close_dir(const struct lu_env *env,
+                                     struct lfsck_component *com)
+{
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct lfsck_assistant_object   *lso    = NULL;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct lfsck_lmv                *llmv   = lfsck->li_lmv;
+       struct lfsck_namespace_req      *lnr;
+       __u32                            size   =
+                               sizeof(*lnr) + LFSCK_TMPBUF_LEN;
+       bool                             wakeup = false;
+       ENTRY;
+
+       if (llmv == NULL)
+               RETURN_EXIT;
+
+       OBD_ALLOC(lnr, size);
+       if (lnr == NULL) {
+               ns->ln_striped_dirs_skipped++;
+
+               RETURN_EXIT;
+       }
+
+       lso = lfsck_assistant_object_init(env, lfsck_dto2fid(lfsck->li_obj_dir),
+                       NULL, lfsck->li_pos_current.lp_oit_cookie, true);
+       if (IS_ERR(lso)) {
+               OBD_FREE(lnr, size);
+               ns->ln_striped_dirs_skipped++;
+
+               RETURN_EXIT;
+       }
+
+       /* Generate a dummy request to indicate that all shards' name entry
+        * in this striped directory has been scanned for the first time. */
+       INIT_LIST_HEAD(&lnr->lnr_lar.lar_list);
+       lnr->lnr_lar.lar_parent = lso;
+       lnr->lnr_lmv = lfsck_lmv_get(llmv);
+       lnr->lnr_fid = *lfsck_dto2fid(lfsck->li_obj_dir);
+       lnr->lnr_dir_cookie = MDS_DIR_END_OFF;
+       lnr->lnr_size = size;
+
+       spin_lock(&lad->lad_lock);
+       if (lad->lad_assistant_status < 0) {
+               spin_unlock(&lad->lad_lock);
+               lfsck_namespace_assistant_req_fini(env, &lnr->lnr_lar);
+               ns->ln_striped_dirs_skipped++;
+
+               RETURN_EXIT;
+       }
+
+       list_add_tail(&lnr->lnr_lar.lar_list, &lad->lad_req_list);
+       if (lad->lad_prefetched == 0)
+               wakeup = true;
+
+       lad->lad_prefetched++;
+       spin_unlock(&lad->lad_lock);
+       if (wakeup)
+               wake_up_all(&lad->lad_thread.t_ctl_waitq);
+
+       EXIT;
+}
+
+static int lfsck_namespace_open_dir(const struct lu_env *env,
+                                   struct lfsck_component *com)
+{
+       struct lfsck_instance   *lfsck  = com->lc_lfsck;
+       struct lfsck_namespace  *ns     = com->lc_file_ram;
+       struct lfsck_lmv        *llmv   = lfsck->li_lmv;
+       int                      rc     = 0;
+       ENTRY;
+
+       if (llmv == NULL)
+               RETURN(0);
+
+       if (llmv->ll_lmv_master) {
+               struct lmv_mds_md_v1 *lmv = &llmv->ll_lmv;
+
+               if (lmv->lmv_master_mdt_index != lfsck_dev_idx(lfsck)) {
+                       lmv->lmv_master_mdt_index =
+                               lfsck_dev_idx(lfsck);
+                       ns->ln_flags |= LF_INCONSISTENT;
+                       llmv->ll_lmv_updated = 1;
+               }
+       } else {
+               rc = lfsck_namespace_verify_stripe_slave(env, com,
+                                       lfsck->li_obj_dir, llmv);
+       }
+
+       RETURN(rc > 0 ? 0 : rc);
+}
+
 static int lfsck_namespace_checkpoint(const struct lu_env *env,
                                      struct lfsck_component *com, bool init)
 {
@@ -2858,15 +4067,15 @@ static int lfsck_namespace_checkpoint(const struct lu_env *env,
                com->lc_new_checked = 0;
        }
 
-       rc = lfsck_namespace_store(env, com, false);
+       rc = lfsck_namespace_store(env, com);
        up_write(&com->lc_sem);
 
 log:
-       CDEBUG(D_LFSCK, "%s: namespace LFSCK checkpoint at the pos ["LPU64
-              ", "DFID", "LPX64"]: rc = %d\n", lfsck_lfsck2name(lfsck),
-              lfsck->li_pos_current.lp_oit_cookie,
+       CDEBUG(D_LFSCK, "%s: namespace LFSCK checkpoint at the pos [%llu"
+              ", "DFID", %#llx], status = %d: rc = %d\n",
+              lfsck_lfsck2name(lfsck), lfsck->li_pos_current.lp_oit_cookie,
               PFID(&lfsck->li_pos_current.lp_dir_parent),
-              lfsck->li_pos_current.lp_dir_cookie, rc);
+              lfsck->li_pos_current.lp_dir_cookie, ns->ln_status, rc);
 
        return rc > 0 ? 0 : rc;
 }
@@ -2880,7 +4089,8 @@ static int lfsck_namespace_prep(const struct lu_env *env,
        struct lfsck_position   *pos    = &com->lc_pos_start;
        int                      rc;
 
-       if (ns->ln_status == LS_COMPLETED) {
+       rc = lfsck_namespace_load_bitmap(env, com);
+       if (rc != 0 || ns->ln_status == LS_COMPLETED) {
                rc = lfsck_namespace_reset(env, com, false);
                if (rc == 0)
                        rc = lfsck_set_param(env, lfsck, lsp->lsp_start, true);
@@ -2928,6 +4138,16 @@ static int lfsck_namespace_prep(const struct lu_env *env,
                        ns->ln_mul_ref_repaired = 0;
                        ns->ln_bad_type_repaired = 0;
                        ns->ln_lost_dirent_repaired = 0;
+                       ns->ln_striped_dirs_scanned = 0;
+                       ns->ln_striped_dirs_repaired = 0;
+                       ns->ln_striped_dirs_failed = 0;
+                       ns->ln_striped_dirs_disabled = 0;
+                       ns->ln_striped_dirs_skipped = 0;
+                       ns->ln_striped_shards_scanned = 0;
+                       ns->ln_striped_shards_repaired = 0;
+                       ns->ln_striped_shards_failed = 0;
+                       ns->ln_striped_shards_skipped = 0;
+                       ns->ln_name_hash_repaired = 0;
                        fid_zero(&ns->ln_fid_latest_scanned_phase2);
                        if (list_empty(&com->lc_link_dir))
                                list_add_tail(&com->lc_link_dir,
@@ -2953,8 +4173,8 @@ static int lfsck_namespace_prep(const struct lu_env *env,
 
        rc = lfsck_start_assistant(env, com, lsp);
 
-       CDEBUG(D_LFSCK, "%s: namespace LFSCK prep done, start pos ["LPU64", "
-              DFID", "LPX64"]: rc = %d\n",
+       CDEBUG(D_LFSCK, "%s: namespace LFSCK prep done, start pos [%llu, "
+              DFID", %#llx]: rc = %d\n",
               lfsck_lfsck2name(lfsck), pos->lp_oit_cookie,
               PFID(&pos->lp_dir_parent), pos->lp_dir_cookie, rc);
 
@@ -2969,15 +4189,12 @@ static int lfsck_namespace_exec_oit(const struct lu_env *env,
        struct lfsck_namespace   *ns    = com->lc_file_ram;
        struct lfsck_instance    *lfsck = com->lc_lfsck;
        const struct lu_fid      *fid   = lfsck_dto2fid(obj);
-       struct lu_attr           *la    = &info->lti_la;
        struct lu_fid            *pfid  = &info->lti_fid2;
        struct lu_name           *cname = &info->lti_name;
        struct lu_seq_range      *range = &info->lti_range;
-       struct dt_device         *dev   = lfsck->li_bottom;
-       struct seq_server_site   *ss    =
-                               lu_site2seq(dev->dd_lu_dev.ld_site);
-       struct linkea_data        ldata = { 0 };
-       __u32                     idx   = lfsck_dev_idx(dev);
+       struct seq_server_site   *ss    = lfsck_dev_site(lfsck);
+       struct linkea_data        ldata = { NULL };
+       __u32                     idx   = lfsck_dev_idx(lfsck);
        int                       rc;
        ENTRY;
 
@@ -3005,20 +4222,8 @@ static int lfsck_namespace_exec_oit(const struct lu_env *env,
                GOTO(out, rc = (rc == -ENOENT ? 0 : rc));
        }
 
-       /* zero-linkEA object may be orphan, but it also maybe because
-        * of upgrading. Currently, we cannot record it for double scan.
-        * Because it may cause the LFSCK tracing file to be too large. */
-       if (rc == -ENODATA) {
-               if (S_ISDIR(lfsck_object_type(obj)))
-                       GOTO(out, rc = 0);
-
-               rc = dt_attr_get(env, obj, la, BYPASS_CAPA);
-               if (rc != 0)
-                       GOTO(out, rc);
-
-               if (la->la_nlink > 1)
-                       rc = lfsck_namespace_trace_update(env, com, fid,
-                                               LNTF_CHECK_LINKEA, true);
+       if (rc == -ENODATA || unlikely(!ldata.ld_leh->leh_reccount)) {
+               rc = lfsck_namespace_check_for_double_scan(env, com, obj);
 
                GOTO(out, rc);
        }
@@ -3044,28 +4249,18 @@ static int lfsck_namespace_exec_oit(const struct lu_env *env,
                rc = fld_local_lookup(env, ss->ss_server_fld,
                                      fid_seq(pfid), range);
                if ((rc == -ENOENT) ||
-                   (rc == 0 && range->lsr_index != idx)) {
+                   (rc == 0 && range->lsr_index != idx))
                        rc = lfsck_namespace_trace_update(env, com, fid,
                                                LNTF_CHECK_LINKEA, true);
-               } else {
-                       if (S_ISDIR(lfsck_object_type(obj)))
-                               GOTO(out, rc = 0);
-
-                       rc = dt_attr_get(env, obj, la, BYPASS_CAPA);
-                       if (rc != 0)
-                               GOTO(out, rc);
-
-                       if (la->la_nlink > 1)
-                               rc = lfsck_namespace_trace_update(env, com,
-                                               fid, LNTF_CHECK_LINKEA, true);
-               }
+               else
+                       rc = lfsck_namespace_check_for_double_scan(env, com,
+                                                                  obj);
        }
 
        GOTO(out, rc);
 
 out:
        down_write(&com->lc_sem);
-       com->lc_new_checked++;
        if (S_ISDIR(lfsck_object_type(obj)))
                ns->ln_dirs_checked++;
        if (rc != 0)
@@ -3077,13 +4272,32 @@ out:
 
 static int lfsck_namespace_exec_dir(const struct lu_env *env,
                                    struct lfsck_component *com,
+                                   struct lfsck_assistant_object *lso,
                                    struct lu_dirent *ent, __u16 type)
 {
-       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct lfsck_assistant_data     *lad     = com->lc_data;
+       struct lfsck_instance           *lfsck   = com->lc_lfsck;
        struct lfsck_namespace_req      *lnr;
-       bool                             wakeup = false;
-
-       lnr = lfsck_namespace_assistant_req_init(com->lc_lfsck, ent, type);
+       struct lfsck_bookmark           *bk      = &lfsck->li_bookmark_ram;
+       struct ptlrpc_thread            *mthread = &lfsck->li_thread;
+       struct ptlrpc_thread            *athread = &lad->lad_thread;
+       struct l_wait_info               lwi     = { 0 };
+       bool                             wakeup  = false;
+
+       l_wait_event(mthread->t_ctl_waitq,
+                    lad->lad_prefetched < bk->lb_async_windows ||
+                    !thread_is_running(mthread) ||
+                    thread_is_stopped(athread),
+                    &lwi);
+
+       if (unlikely(!thread_is_running(mthread)) ||
+                    thread_is_stopped(athread))
+               return 0;
+
+       if (unlikely(lfsck_is_dead_obj(lfsck->li_obj_dir)))
+               return 0;
+
+       lnr = lfsck_namespace_assistant_req_init(com->lc_lfsck, lso, ent, type);
        if (IS_ERR(lnr)) {
                struct lfsck_namespace *ns = com->lc_file_ram;
 
@@ -3126,6 +4340,8 @@ static int lfsck_namespace_post(const struct lu_env *env,
        lfsck_post_generic(env, com, &result);
 
        down_write(&com->lc_sem);
+       lfsck_namespace_release_lmv(env, com);
+
        spin_lock(&lfsck->li_lock);
        if (!init)
                ns->ln_pos_last_checkpoint = lfsck->li_pos_checkpoint;
@@ -3136,8 +4352,9 @@ static int lfsck_namespace_post(const struct lu_env *env,
                list_del_init(&com->lc_link_dir);
                list_move_tail(&com->lc_link, &lfsck->li_list_double_scan);
        } else if (result == 0) {
-               ns->ln_status = lfsck->li_status;
-               if (ns->ln_status == 0)
+               if (lfsck->li_status != 0)
+                       ns->ln_status = lfsck->li_status;
+               else
                        ns->ln_status = LS_STOPPED;
                if (ns->ln_status != LS_PAUSED) {
                        list_del_init(&com->lc_link_dir);
@@ -3158,7 +4375,7 @@ static int lfsck_namespace_post(const struct lu_env *env,
                com->lc_new_checked = 0;
        }
 
-       rc = lfsck_namespace_store(env, com, false);
+       rc = lfsck_namespace_store(env, com);
        up_write(&com->lc_sem);
 
        CDEBUG(D_LFSCK, "%s: namespace LFSCK post done: rc = %d\n",
@@ -3167,14 +4384,13 @@ static int lfsck_namespace_post(const struct lu_env *env,
        RETURN(rc);
 }
 
-static int
+static void
 lfsck_namespace_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_namespace  *ns    = com->lc_file_ram;
-       int                      rc;
 
        down_read(&com->lc_sem);
        seq_printf(m, "name: lfsck_namespace\n"
@@ -3183,45 +4399,25 @@ lfsck_namespace_dump(const struct lu_env *env, struct lfsck_component *com,
                   "status: %s\n",
                   ns->ln_magic,
                   bk->lb_version,
-                  lfsck_status2names(ns->ln_status));
+                  lfsck_status2name(ns->ln_status));
 
-       rc = lfsck_bits_dump(m, ns->ln_flags, lfsck_flags_names, "flags");
-       if (rc < 0)
-               goto out;
+       lfsck_bits_dump(m, ns->ln_flags, lfsck_flags_names, "flags");
 
-       rc = lfsck_bits_dump(m, bk->lb_param, lfsck_param_names, "param");
-       if (rc < 0)
-               goto out;
+       lfsck_bits_dump(m, bk->lb_param, lfsck_param_names, "param");
 
-       rc = lfsck_time_dump(m, ns->ln_time_last_complete,
-                            "time_since_last_completed");
-       if (rc < 0)
-               goto out;
+       lfsck_time_dump(m, ns->ln_time_last_complete, "last_completed");
 
-       rc = lfsck_time_dump(m, ns->ln_time_latest_start,
-                            "time_since_latest_start");
-       if (rc < 0)
-               goto out;
+       lfsck_time_dump(m, ns->ln_time_latest_start, "latest_start");
 
-       rc = lfsck_time_dump(m, ns->ln_time_last_checkpoint,
-                            "time_since_last_checkpoint");
-       if (rc < 0)
-               goto out;
+       lfsck_time_dump(m, ns->ln_time_last_checkpoint, "last_checkpoint");
 
-       rc = lfsck_pos_dump(m, &ns->ln_pos_latest_start,
-                           "latest_start_position");
-       if (rc < 0)
-               goto out;
+       lfsck_pos_dump(m, &ns->ln_pos_latest_start, "latest_start_position");
 
-       rc = lfsck_pos_dump(m, &ns->ln_pos_last_checkpoint,
-                           "last_checkpoint_position");
-       if (rc < 0)
-               goto out;
+       lfsck_pos_dump(m, &ns->ln_pos_last_checkpoint,
+                      "last_checkpoint_position");
 
-       rc = lfsck_pos_dump(m, &ns->ln_pos_first_inconsistent,
-                           "first_failure_position");
-       if (rc < 0)
-               goto out;
+       lfsck_pos_dump(m, &ns->ln_pos_first_inconsistent,
+                      "first_failure_position");
 
        if (ns->ln_status == LS_SCANNING_PHASE1) {
                struct lfsck_position pos;
@@ -3230,24 +4426,26 @@ lfsck_namespace_dump(const struct lu_env *env, struct lfsck_component *com,
                                          lfsck->li_time_last_checkpoint;
                __u64 checked = ns->ln_items_checked + com->lc_new_checked;
                __u64 speed = checked;
-               __u64 new_checked = com->lc_new_checked * HZ;
+               __u64 new_checked = com->lc_new_checked *
+                                   msecs_to_jiffies(MSEC_PER_SEC);
                __u32 rtime = ns->ln_run_time_phase1 +
                              cfs_duration_sec(duration + HALF_SEC);
 
                if (duration != 0)
                        do_div(new_checked, duration);
+
                if (rtime != 0)
                        do_div(speed, rtime);
-               lfsck_namespace_dump_statistics(m, ns, checked,
-                                               ns->ln_objs_checked_phase2,
-                                               rtime, ns->ln_run_time_phase2);
 
-               seq_printf(m, "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",
-                             speed,
-                             new_checked);
+               lfsck_namespace_dump_statistics(m, ns, checked, 0, rtime, 0);
+               seq_printf(m, "average_speed_phase1: %llu items/sec\n"
+                          "average_speed_phase2: N/A\n"
+                          "average_speed_total: %llu items/sec\n"
+                          "real_time_speed_phase1: %llu items/sec\n"
+                          "real_time_speed_phase2: N/A\n",
+                          speed,
+                          speed,
+                          new_checked);
 
                LASSERT(lfsck->li_di_oit != NULL);
 
@@ -3279,66 +4477,109 @@ lfsck_namespace_dump(const struct lu_env *env, struct lfsck_component *com,
                lfsck_pos_dump(m, &pos, "current_position");
        } else if (ns->ln_status == LS_SCANNING_PHASE2) {
                cfs_duration_t duration = cfs_time_current() -
-                                         lfsck->li_time_last_checkpoint;
+                                         com->lc_time_last_checkpoint;
                __u64 checked = ns->ln_objs_checked_phase2 +
                                com->lc_new_checked;
                __u64 speed1 = ns->ln_items_checked;
                __u64 speed2 = checked;
-               __u64 new_checked = com->lc_new_checked * HZ;
+               __u64 speed0 = speed1 + speed2;
+               __u64 new_checked = com->lc_new_checked *
+                                   msecs_to_jiffies(MSEC_PER_SEC);
                __u32 rtime = ns->ln_run_time_phase2 +
                              cfs_duration_sec(duration + HALF_SEC);
+               __u32 time0 = ns->ln_run_time_phase1 + rtime;
 
                if (duration != 0)
                        do_div(new_checked, duration);
+
                if (ns->ln_run_time_phase1 != 0)
                        do_div(speed1, ns->ln_run_time_phase1);
+               else if (ns->ln_items_checked != 0)
+                       time0++;
+
                if (rtime != 0)
                        do_div(speed2, rtime);
+               else if (checked != 0)
+                       time0++;
+
+               if (time0 != 0)
+                       do_div(speed0, time0);
+
                lfsck_namespace_dump_statistics(m, ns, ns->ln_items_checked,
                                                checked,
                                                ns->ln_run_time_phase1, rtime);
-
-               seq_printf(m, "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: "LPU64" objs/sec\n"
-                             "current_position: "DFID"\n",
-                             speed1,
-                             speed2,
-                             new_checked,
-                             PFID(&ns->ln_fid_latest_scanned_phase2));
+               seq_printf(m, "average_speed_phase1: %llu items/sec\n"
+                          "average_speed_phase2: %llu objs/sec\n"
+                          "average_speed_total: %llu items/sec\n"
+                          "real_time_speed_phase1: N/A\n"
+                          "real_time_speed_phase2: %llu objs/sec\n"
+                          "current_position: "DFID"\n",
+                          speed1,
+                          speed2,
+                          speed0,
+                          new_checked,
+                          PFID(&ns->ln_fid_latest_scanned_phase2));
        } else {
                __u64 speed1 = ns->ln_items_checked;
                __u64 speed2 = ns->ln_objs_checked_phase2;
+               __u64 speed0 = speed1 + speed2;
+               __u32 time0 = ns->ln_run_time_phase1 + ns->ln_run_time_phase2;
 
                if (ns->ln_run_time_phase1 != 0)
                        do_div(speed1, ns->ln_run_time_phase1);
+               else if (ns->ln_items_checked != 0)
+                       time0++;
+
                if (ns->ln_run_time_phase2 != 0)
                        do_div(speed2, ns->ln_run_time_phase2);
+               else if (ns->ln_objs_checked_phase2 != 0)
+                       time0++;
+
+               if (time0 != 0)
+                       do_div(speed0, time0);
+
                lfsck_namespace_dump_statistics(m, ns, ns->ln_items_checked,
                                                ns->ln_objs_checked_phase2,
                                                ns->ln_run_time_phase1,
                                                ns->ln_run_time_phase2);
-
-               seq_printf(m, "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",
-                             speed1,
-                             speed2);
+               seq_printf(m, "average_speed_phase1: %llu items/sec\n"
+                          "average_speed_phase2: %llu objs/sec\n"
+                          "average_speed_total: %llu items/sec\n"
+                          "real_time_speed_phase1: N/A\n"
+                          "real_time_speed_phase2: N/A\n"
+                          "current_position: N/A\n",
+                          speed1,
+                          speed2,
+                          speed0);
        }
-out:
+
        up_read(&com->lc_sem);
-       return 0;
 }
 
 static int lfsck_namespace_double_scan(const struct lu_env *env,
                                       struct lfsck_component *com)
 {
-       struct lfsck_namespace *ns = com->lc_file_ram;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct lfsck_tgt_descs          *ltds   = &com->lc_lfsck->li_mdt_descs;
+       struct lfsck_tgt_desc           *ltd;
+       struct lfsck_tgt_desc           *next;
+       int                              rc;
+
+       rc = lfsck_double_scan_generic(env, com, ns->ln_status);
+       if (thread_is_stopped(&lad->lad_thread)) {
+               LASSERT(list_empty(&lad->lad_req_list));
+               LASSERT(list_empty(&lad->lad_mdt_phase1_list));
+
+               spin_lock(&ltds->ltd_lock);
+               list_for_each_entry_safe(ltd, next, &lad->lad_mdt_phase2_list,
+                                        ltd_namespace_phase_list) {
+                       list_del_init(&ltd->ltd_namespace_phase_list);
+               }
+               spin_unlock(&ltds->ltd_lock);
+       }
 
-       return lfsck_double_scan_generic(env, com, ns->ln_status);
+       return rc;
 }
 
 static void lfsck_namespace_data_release(const struct lu_env *env,
@@ -3355,6 +4596,7 @@ static void lfsck_namespace_data_release(const struct lu_env *env,
        LASSERT(list_empty(&lad->lad_req_list));
 
        com->lc_data = NULL;
+       lfsck_namespace_release_lmv(env, com);
 
        spin_lock(&ltds->ltd_lock);
        list_for_each_entry_safe(ltd, next, &lad->lad_mdt_phase1_list,
@@ -3371,34 +4613,95 @@ static void lfsck_namespace_data_release(const struct lu_env *env,
        }
        spin_unlock(&ltds->ltd_lock);
 
-       CFS_FREE_BITMAP(lad->lad_bitmap);
+       if (likely(lad->lad_bitmap != NULL))
+               CFS_FREE_BITMAP(lad->lad_bitmap);
 
        OBD_FREE_PTR(lad);
 }
 
+static void lfsck_namespace_quit(const struct lu_env *env,
+                                struct lfsck_component *com)
+{
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct lfsck_tgt_descs          *ltds   = &com->lc_lfsck->li_mdt_descs;
+       struct lfsck_tgt_desc           *ltd;
+       struct lfsck_tgt_desc           *next;
+
+       LASSERT(lad != NULL);
+
+       lfsck_quit_generic(env, com);
+
+       LASSERT(thread_is_init(&lad->lad_thread) ||
+               thread_is_stopped(&lad->lad_thread));
+       LASSERT(list_empty(&lad->lad_req_list));
+
+       lfsck_namespace_release_lmv(env, com);
+
+       spin_lock(&ltds->ltd_lock);
+       list_for_each_entry_safe(ltd, next, &lad->lad_mdt_phase1_list,
+                                ltd_namespace_phase_list) {
+               list_del_init(&ltd->ltd_namespace_phase_list);
+       }
+       list_for_each_entry_safe(ltd, next, &lad->lad_mdt_phase2_list,
+                                ltd_namespace_phase_list) {
+               list_del_init(&ltd->ltd_namespace_phase_list);
+       }
+       spin_unlock(&ltds->ltd_lock);
+}
+
 static int lfsck_namespace_in_notify(const struct lu_env *env,
                                     struct lfsck_component *com,
-                                    struct lfsck_request *lr)
+                                    struct lfsck_request *lr,
+                                    struct thandle *th)
 {
        struct lfsck_instance           *lfsck = com->lc_lfsck;
        struct lfsck_namespace          *ns    = com->lc_file_ram;
        struct lfsck_assistant_data     *lad   = com->lc_data;
        struct lfsck_tgt_descs          *ltds  = &lfsck->li_mdt_descs;
        struct lfsck_tgt_desc           *ltd;
+       int                              rc    = 0;
        bool                             fail  = false;
        ENTRY;
 
-       if (lr->lr_event != LE_PHASE1_DONE &&
-           lr->lr_event != LE_PHASE2_DONE &&
-           lr->lr_event != LE_PEER_EXIT)
+       switch (lr->lr_event) {
+       case LE_SET_LMV_MASTER: {
+               struct dt_object        *obj;
+
+               obj = lfsck_object_find_bottom(env, lfsck, &lr->lr_fid);
+               if (IS_ERR(obj))
+                       RETURN(PTR_ERR(obj));
+
+               if (likely(dt_object_exists(obj)))
+                       rc = lfsck_namespace_notify_lmv_master_local(env, com,
+                                                                    obj);
+
+               lfsck_object_put(env, obj);
+
+               RETURN(rc > 0 ? 0 : rc);
+       }
+       case LE_SET_LMV_SLAVE: {
+               if (!(lr->lr_flags & LEF_RECHECK_NAME_HASH))
+                       ns->ln_striped_shards_repaired++;
+
+               rc = lfsck_namespace_trace_update(env, com, &lr->lr_fid,
+                                                 LNTF_RECHECK_NAME_HASH, true);
+
+               RETURN(rc > 0 ? 0 : rc);
+       }
+       case LE_PHASE1_DONE:
+       case LE_PHASE2_DONE:
+       case LE_PEER_EXIT:
+               break;
+       default:
                RETURN(-EINVAL);
+       }
 
        CDEBUG(D_LFSCK, "%s: namespace LFSCK handles notify %u from MDT %x, "
-              "status %d\n", lfsck_lfsck2name(lfsck), lr->lr_event,
-              lr->lr_index, lr->lr_status);
+              "status %d, flags %x\n", lfsck_lfsck2name(lfsck), lr->lr_event,
+              lr->lr_index, lr->lr_status, lr->lr_flags2);
 
        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);
 
@@ -3420,6 +4723,9 @@ static int lfsck_namespace_in_notify(const struct lu_env *env,
                        break;
                }
 
+               if (lr->lr_flags2 & LF_INCOMPLETE)
+                       ns->ln_flags |= LF_INCOMPLETE;
+
                if (list_empty(&ltd->ltd_namespace_list))
                        list_add_tail(&ltd->ltd_namespace_list,
                                      &lad->lad_mdt_list);
@@ -3460,17 +4766,88 @@ static int lfsck_namespace_in_notify(const struct lu_env *env,
        RETURN(0);
 }
 
+static void lfsck_namespace_repaired(struct lfsck_namespace *ns, __u64 *count)
+{
+       *count += ns->ln_objs_nlink_repaired;
+       *count += ns->ln_dirent_repaired;
+       *count += ns->ln_linkea_repaired;
+       *count += ns->ln_mul_linked_repaired;
+       *count += ns->ln_unmatched_pairs_repaired;
+       *count += ns->ln_dangling_repaired;
+       *count += ns->ln_mul_ref_repaired;
+       *count += ns->ln_bad_type_repaired;
+       *count += ns->ln_lost_dirent_repaired;
+       *count += ns->ln_striped_dirs_disabled;
+       *count += ns->ln_striped_dirs_repaired;
+       *count += ns->ln_striped_shards_repaired;
+       *count += ns->ln_name_hash_repaired;
+       *count += ns->ln_local_lpf_moved;
+}
+
+static int lfsck_namespace_query_all(const struct lu_env *env,
+                                    struct lfsck_component *com,
+                                    __u32 *mdts_count, __u64 *repaired)
+{
+       struct lfsck_namespace *ns = com->lc_file_ram;
+       struct lfsck_tgt_descs *ltds = &com->lc_lfsck->li_mdt_descs;
+       struct lfsck_tgt_desc *ltd;
+       int idx;
+       int rc;
+       ENTRY;
+
+       rc = lfsck_query_all(env, com);
+       if (rc != 0)
+               RETURN(rc);
+
+       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_namespace_status]++;
+               *repaired += ltd->ltd_namespace_repaired;
+       }
+       up_read(&ltds->ltd_rw_sem);
+
+       down_read(&com->lc_sem);
+       mdts_count[ns->ln_status]++;
+       lfsck_namespace_repaired(ns, repaired);
+       up_read(&com->lc_sem);
+
+       RETURN(0);
+}
+
 static int lfsck_namespace_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_namespace *ns = com->lc_file_ram;
+       int rc = 0;
+
+       if (que != NULL) {
+               LASSERT(com->lc_lfsck->li_master);
 
-       return ns->ln_status;
+               rc = lfsck_namespace_query_all(env, com,
+                                              que->lu_mdts_count[idx],
+                                              &que->lu_repaired[idx]);
+       } else {
+               down_read(&com->lc_sem);
+               rep->lr_status = ns->ln_status;
+               if (req->lr_flags & LEF_QUERY_ALL)
+                       lfsck_namespace_repaired(ns, &rep->lr_repaired);
+               up_read(&com->lc_sem);
+       }
+
+       return rc;
 }
 
 static struct lfsck_operations lfsck_namespace_ops = {
        .lfsck_reset            = lfsck_namespace_reset,
        .lfsck_fail             = lfsck_namespace_fail,
+       .lfsck_close_dir        = lfsck_namespace_close_dir,
+       .lfsck_open_dir         = lfsck_namespace_open_dir,
        .lfsck_checkpoint       = lfsck_namespace_checkpoint,
        .lfsck_prep             = lfsck_namespace_prep,
        .lfsck_exec_oit         = lfsck_namespace_exec_oit,
@@ -3479,7 +4856,7 @@ static struct lfsck_operations lfsck_namespace_ops = {
        .lfsck_dump             = lfsck_namespace_dump,
        .lfsck_double_scan      = lfsck_namespace_double_scan,
        .lfsck_data_release     = lfsck_namespace_data_release,
-       .lfsck_quit             = lfsck_quit_generic,
+       .lfsck_quit             = lfsck_namespace_quit,
        .lfsck_in_notify        = lfsck_namespace_in_notify,
        .lfsck_query            = lfsck_namespace_query,
 };
@@ -3495,10 +4872,12 @@ static struct lfsck_operations lfsck_namespace_ops = {
  *    and the users can make the decision about how to handle it with
  *    more human knownledge. (by default)
  *
- * 2) Re-create the missed MDT-object with the FID information.
+ * 2) Re-create the missing MDT-object with the FID information.
  *
  * \param[in] env      pointer to the thread context
  * \param[in] com      pointer to the lfsck component
+ * \param[in] parent   pointer to the dir object that contains the dangling
+ *                     name entry
  * \param[in] child    pointer to the object corresponding to the dangling
  *                     name entry
  * \param[in] lnr      pointer to the namespace request that contains the
@@ -3510,6 +4889,7 @@ static struct lfsck_operations lfsck_namespace_ops = {
  */
 int lfsck_namespace_repair_dangling(const struct lu_env *env,
                                    struct lfsck_component *com,
+                                   struct dt_object *parent,
                                    struct dt_object *child,
                                    struct lfsck_namespace_req *lnr)
 {
@@ -3518,14 +4898,17 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
        struct dt_allocation_hint       *hint   = &info->lti_hint;
        struct dt_object_format         *dof    = &info->lti_dof;
        struct dt_insert_rec            *rec    = &info->lti_dt_rec;
-       struct dt_object                *parent = lnr->lnr_obj;
+       struct lmv_mds_md_v1            *lmv2   = &info->lti_lmv2;
        const struct lu_name            *cname;
-       struct linkea_data               ldata  = { 0 };
-       struct lustre_handle             lh     = { 0 };
+       const struct lu_fid             *pfid   = lfsck_dto2fid(parent);
+       const struct lu_fid             *cfid   = lfsck_dto2fid(child);
+       struct linkea_data               ldata  = { NULL };
+       struct lfsck_lock_handle        *llh    = &info->lti_llh;
        struct lu_buf                    linkea_buf;
+       struct lu_buf                    lmv_buf;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
        struct lfsck_bookmark           *bk     = &lfsck->li_bookmark_ram;
-       struct dt_device                *dev    = lfsck_obj2dt_dev(child);
+       struct dt_device                *dev    = lfsck->li_next;
        struct thandle                  *th     = NULL;
        int                              rc     = 0;
        __u16                            type   = lnr->lnr_type;
@@ -3541,16 +4924,27 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
        if (!create || bk->lb_param & LPF_DRYRUN)
                GOTO(log, rc = 0);
 
-       rc = linkea_data_new(&ldata, &info->lti_linkea_buf2);
-       if (rc != 0)
-               GOTO(log, rc);
+       /* We may need to create the sub-objects of the @child via LOD,
+        * so make the modification based on lfsck->li_next. */
+
+       parent = lfsck_object_locate(dev, parent);
+       if (IS_ERR(parent))
+               GOTO(log, rc = PTR_ERR(parent));
+
+       if (unlikely(!dt_try_as_dir(env, parent)))
+               GOTO(log, rc = -ENOTDIR);
 
-       rc = linkea_add_buf(&ldata, cname, lfsck_dto2fid(parent));
+       child = lfsck_object_locate(dev, child);
+       if (IS_ERR(child))
+               GOTO(log, rc = PTR_ERR(child));
+
+       rc = linkea_links_new(&ldata, &info->lti_linkea_buf2,
+                             cname, pfid);
        if (rc != 0)
                GOTO(log, rc);
 
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       rc = lfsck_lock(env, lfsck, parent, lnr->lnr_name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PR);
        if (rc != 0)
                GOTO(log, rc);
 
@@ -3558,10 +4952,6 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
        if (rc != 0)
                GOTO(log, rc);
 
-       th = dt_trans_create(env, dev);
-       if (IS_ERR(th))
-               GOTO(log, rc = PTR_ERR(th));
-
        /* Set the ctime as zero, then others can know it is created for
         * repairing dangling name entry by LFSCK. And if the LFSCK made
         * wrong decision and the real MDT-object has been found later,
@@ -3572,7 +4962,7 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
                        LA_ATIME | LA_MTIME | LA_CTIME;
 
        child->do_ops->do_ah_init(env, hint, parent, child,
-                                 la->la_mode & S_IFMT);
+                                la->la_mode & S_IFMT);
 
        memset(dof, 0, sizeof(*dof));
        dof->dof_type = dt_mode_to_dft(type);
@@ -3580,6 +4970,10 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
         * the MDT-object without stripes (dof->dof_reg.striped = 0). related
         * OST-objects will be created when write open. */
 
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(log, rc = PTR_ERR(th));
+
        /* 1a. create child. */
        rc = dt_declare_create(env, child, la, hint, dof, th);
        if (rc != 0)
@@ -3589,30 +4983,52 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
                if (unlikely(!dt_try_as_dir(env, child)))
                        GOTO(stop, rc = -ENOTDIR);
 
-               /* 2a. insert dot into child dir */
+               /* 2a. increase child nlink */
+               rc = dt_declare_ref_add(env, child, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+
+               /* 3a. insert dot into child dir */
                rec->rec_type = S_IFDIR;
-               rec->rec_fid = lfsck_dto2fid(child);
+               rec->rec_fid = cfid;
                rc = dt_declare_insert(env, child,
                                       (const struct dt_rec *)rec,
                                       (const struct dt_key *)dot, th);
                if (rc != 0)
                        GOTO(stop, rc);
 
-               /* 3a. insert dotdot into child dir */
-               rec->rec_fid = lfsck_dto2fid(parent);
+               /* 4a. insert dotdot into child dir */
+               rec->rec_fid = pfid;
                rc = dt_declare_insert(env, child,
                                       (const struct dt_rec *)rec,
                                       (const struct dt_key *)dotdot, th);
                if (rc != 0)
                        GOTO(stop, rc);
 
-               /* 4a. increase child nlink */
-               rc = dt_declare_ref_add(env, child, th);
-               if (rc != 0)
-                       GOTO(stop, rc);
+               /* 5a. generate slave LMV EA. */
+               if (lnr->lnr_lmv != NULL && lnr->lnr_lmv->ll_lmv_master) {
+                       int idx;
+
+                       idx = lfsck_shard_name_to_index(env,
+                                       lnr->lnr_name, lnr->lnr_namelen,
+                                       type, cfid);
+                       if (unlikely(idx < 0))
+                               GOTO(stop, rc = idx);
+
+                       *lmv2 = lnr->lnr_lmv->ll_lmv;
+                       lmv2->lmv_magic = LMV_MAGIC_STRIPE;
+                       lmv2->lmv_master_mdt_index = idx;
+
+                       lfsck_lmv_header_cpu_to_le(lmv2, lmv2);
+                       lfsck_buf_init(&lmv_buf, lmv2, sizeof(*lmv2));
+                       rc = dt_declare_xattr_set(env, child, &lmv_buf,
+                                                 XATTR_NAME_LMV, 0, th);
+                       if (rc != 0)
+                               GOTO(stop, rc);
+               }
        }
 
-       /* 5a. insert linkEA for child */
+       /* 6a. insert linkEA for child */
        lfsck_buf_init(&linkea_buf, ldata.ld_buf->lb_buf,
                       ldata.ld_leh->leh_len);
        rc = dt_declare_xattr_set(env, child, &linkea_buf,
@@ -3620,7 +5036,7 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_trans_start(env, dev, th);
+       rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc = (rc == -EEXIST ? 1 : rc));
 
@@ -3631,34 +5047,38 @@ int lfsck_namespace_repair_dangling(const struct lu_env *env,
                GOTO(unlock, rc = (rc == -EEXIST ? 1 : rc));
 
        if (S_ISDIR(type)) {
-               if (unlikely(!dt_try_as_dir(env, child)))
-                       GOTO(unlock, rc = -ENOTDIR);
+               /* 2b. increase child nlink */
+               rc = dt_ref_add(env, child, th);
+               if (rc != 0)
+                       GOTO(unlock, rc);
 
-               /* 2b. insert dot into child dir */
+               /* 3b. insert dot into child dir */
                rec->rec_type = S_IFDIR;
-               rec->rec_fid = lfsck_dto2fid(child);
+               rec->rec_fid = cfid;
                rc = dt_insert(env, child, (const struct dt_rec *)rec,
-                              (const struct dt_key *)dot, th, BYPASS_CAPA, 1);
+                              (const struct dt_key *)dot, th, 1);
                if (rc != 0)
                        GOTO(unlock, rc);
 
-               /* 3b. insert dotdot into child dir */
-               rec->rec_fid = lfsck_dto2fid(parent);
+               /* 4b. insert dotdot into child dir */
+               rec->rec_fid = pfid;
                rc = dt_insert(env, child, (const struct dt_rec *)rec,
-                              (const struct dt_key *)dotdot, th,
-                              BYPASS_CAPA, 1);
+                              (const struct dt_key *)dotdot, th, 1);
                if (rc != 0)
                        GOTO(unlock, rc);
 
-               /* 4b. increase child nlink */
-               rc = dt_ref_add(env, child, th);
-               if (rc != 0)
-                       GOTO(unlock, rc);
+               /* 5b. generate slave LMV EA. */
+               if (lnr->lnr_lmv != NULL && lnr->lnr_lmv->ll_lmv_master) {
+                       rc = dt_xattr_set(env, child, &lmv_buf, XATTR_NAME_LMV,
+                                         0, th);
+                       if (rc != 0)
+                               GOTO(unlock, rc);
+               }
        }
 
-       /* 5b. insert linkEA for child. */
+       /* 6b. insert linkEA for child. */
        rc = dt_xattr_set(env, child, &linkea_buf,
-                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
+                         XATTR_NAME_LINK, 0, th);
 
        GOTO(unlock, rc);
 
@@ -3669,13 +5089,12 @@ stop:
        dt_trans_stop(env, dev, th);
 
 log:
-       lfsck_ibits_unlock(&lh, LCK_EX);
+       lfsck_unlock(llh);
        CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant found dangling "
               "reference for: parent "DFID", child "DFID", type %u, "
               "name %s. %s: rc = %d\n", lfsck_lfsck2name(lfsck),
-              PFID(lfsck_dto2fid(parent)), PFID(lfsck_dto2fid(child)),
-              type, cname->ln_name,
-              create ? "Create the lost OST-object as required" :
+              PFID(pfid), PFID(cfid), type, cname->ln_name,
+              create ? "Create the lost MDT-object as required" :
                        "Keep the MDT-object there by default", rc);
 
        if (rc <= 0) {
@@ -3696,27 +5115,35 @@ static int lfsck_namespace_assistant_handler_p1(const struct lu_env *env,
        struct lfsck_instance      *lfsck    = com->lc_lfsck;
        struct lfsck_bookmark      *bk       = &lfsck->li_bookmark_ram;
        struct lfsck_namespace     *ns       = com->lc_file_ram;
-       struct linkea_data          ldata    = { 0 };
+       struct lfsck_assistant_data *lad     = com->lc_data;
+       struct linkea_data          ldata    = { NULL };
        const struct lu_name       *cname;
        struct thandle             *handle   = NULL;
        struct lfsck_namespace_req *lnr      =
                        container_of0(lar, struct lfsck_namespace_req, lnr_lar);
-       struct dt_object           *dir      = lnr->lnr_obj;
+       struct dt_object           *dir      = NULL;
        struct dt_object           *obj      = NULL;
-       const struct lu_fid        *pfid     = lfsck_dto2fid(dir);
-       struct dt_device           *dev;
+       struct lfsck_assistant_object *lso   = lar->lar_parent;
+       const struct lu_fid        *pfid     = &lso->lso_fid;
+       struct dt_device           *dev      = NULL;
        struct lustre_handle        lh       = { 0 };
        bool                        repaired = false;
        bool                        dtlocked = false;
        bool                        remove;
        bool                        newdata;
        bool                        log      = false;
-       int                         idx;
+       bool                        bad_hash = false;
+       bool                        bad_linkea = false;
+       int                         idx      = 0;
        int                         count    = 0;
-       int                         rc;
+       int                         rc       = 0;
        enum lfsck_namespace_inconsistency_type type = LNIT_NONE;
        ENTRY;
 
+       if (lso->lso_dead)
+               RETURN(0);
+
+       la->la_nlink = 0;
        if (lnr->lnr_attr & LUDA_UPGRADE) {
                ns->ln_flags |= LF_UPGRADE;
                ns->ln_dirent_repaired++;
@@ -3737,19 +5164,48 @@ static int lfsck_namespace_assistant_handler_p1(const struct lu_env *env,
                GOTO(out, rc);
        }
 
-       if (lnr->lnr_name[0] == '.' &&
-           (lnr->lnr_namelen == 1 || fid_seq_is_dot(fid_seq(&lnr->lnr_fid))))
+       if (unlikely(!fid_is_sane(&lnr->lnr_fid))) {
+               CDEBUG(D_LFSCK, "%s: dir scan find invalid FID "DFID
+                      " for the name entry %.*s under "DFID"\n",
+                      lfsck_lfsck2name(lfsck), PFID(&lnr->lnr_fid),
+                      lnr->lnr_namelen, lnr->lnr_name, PFID(pfid));
+
+               if (strcmp(lnr->lnr_name, dotdot) != 0)
+                       /* invalid FID means bad name entry, remove it. */
+                       type = LNIT_BAD_DIRENT;
+               else
+                       /* If the parent FID is invalid, we cannot remove
+                        * the ".." entry directly. */
+                       rc = lfsck_namespace_trace_update(env, com, pfid,
+                                               LNTF_CHECK_PARENT, true);
+
+               GOTO(out, rc);
+       }
+
+       if (unlikely(lnr->lnr_dir_cookie == MDS_DIR_END_OFF)) {
+               rc = lfsck_namespace_striped_dir_rescan(env, com, lnr);
+
+               RETURN(rc);
+       }
+
+       if (fid_seq_is_dot(fid_seq(&lnr->lnr_fid)))
                GOTO(out, rc = 0);
 
+       if (lnr->lnr_lmv != NULL && lnr->lnr_lmv->ll_lmv_master) {
+               rc = lfsck_namespace_handle_striped_master(env, com, lnr);
+
+               RETURN(rc);
+       }
+
        idx = lfsck_find_mdt_idx_by_fid(env, lfsck, &lnr->lnr_fid);
        if (idx < 0)
                GOTO(out, rc = idx);
 
-       if (idx == lfsck_dev_idx(lfsck->li_bottom)) {
+       if (idx == lfsck_dev_idx(lfsck)) {
                if (unlikely(strcmp(lnr->lnr_name, dotdot) == 0))
                        GOTO(out, rc = 0);
 
-               dev = lfsck->li_next;
+               dev = lfsck->li_bottom;
        } else {
                struct lfsck_tgt_desc *ltd;
 
@@ -3763,12 +5219,12 @@ static int lfsck_namespace_assistant_handler_p1(const struct lu_env *env,
                        GOTO(out, rc);
                }
 
-               ltd = LTD_TGT(&lfsck->li_mdt_descs, idx);
+               ltd = lfsck_ltd2tgt(&lfsck->li_mdt_descs, idx);
                if (unlikely(ltd == NULL)) {
                        CDEBUG(D_LFSCK, "%s: cannot talk with MDT %x which "
                               "did not join the namespace LFSCK\n",
                               lfsck_lfsck2name(lfsck), idx);
-                       ns->ln_flags |= LF_INCOMPLETE;
+                       lfsck_lad_set_bitmap(env, com, idx);
 
                        GOTO(out, rc = -ENODEV);
                }
@@ -3784,10 +5240,26 @@ static int lfsck_namespace_assistant_handler_p1(const struct lu_env *env,
        if (dt_object_exists(obj) == 0) {
 
 dangling:
+               if (dir == NULL) {
+                       dir = lfsck_assistant_object_load(env, lfsck, lso);
+                       if (IS_ERR(dir)) {
+                               rc = PTR_ERR(dir);
+
+                               GOTO(trace, rc == -ENOENT ? 0 : rc);
+                       }
+               }
+
                rc = lfsck_namespace_check_exist(env, dir, obj, lnr->lnr_name);
                if (rc == 0) {
+                       if (!lfsck_is_valid_slave_name_entry(env, lnr->lnr_lmv,
+                                       lnr->lnr_name, lnr->lnr_namelen)) {
+                               type = LNIT_BAD_DIRENT;
+
+                               GOTO(out, rc);
+                       }
+
                        type = LNIT_DANGLING;
-                       rc = lfsck_namespace_repair_dangling(env, com,
+                       rc = lfsck_namespace_repair_dangling(env, com, dir,
                                                             obj, lnr);
                        if (rc == 0)
                                repaired = true;
@@ -3796,7 +5268,7 @@ dangling:
                GOTO(out, rc);
        }
 
-       if (!(bk->lb_param & LPF_DRYRUN) && repaired) {
+       if (!(bk->lb_param & LPF_DRYRUN) && lad->lad_advance_lock) {
 
 again:
                rc = lfsck_ibits_lock(env, lfsck, obj, &lh,
@@ -3813,7 +5285,7 @@ again:
                if (rc != 0)
                        GOTO(stop, rc);
 
-               rc = dt_trans_start(env, dev, handle);
+               rc = dt_trans_start_local(env, dev, handle);
                if (rc != 0)
                        GOTO(stop, rc);
 
@@ -3821,10 +5293,6 @@ again:
                dtlocked = true;
        }
 
-       rc = lfsck_namespace_check_exist(env, dir, obj, lnr->lnr_name);
-       if (rc != 0)
-               GOTO(stop, rc);
-
        rc = lfsck_links_read(env, obj, &ldata);
        if (unlikely(rc == -ENOENT)) {
                if (handle != NULL) {
@@ -3851,16 +5319,26 @@ again:
                                type = LNIT_BAD_TYPE;
                        }
 
-                       goto record;
+                       goto stop;
                }
 
-               ns->ln_flags |= LF_INCONSISTENT;
+               /* If the name entry hash does not match the slave striped
+                * directory, and the name entry does not match also, then
+                * it is quite possible that name entry is corrupted. */
+               if (!lfsck_is_valid_slave_name_entry(env, lnr->lnr_lmv,
+                                       lnr->lnr_name, lnr->lnr_namelen)) {
+                       ns->ln_flags |= LF_INCONSISTENT;
+                       type = LNIT_BAD_DIRENT;
+
+                       GOTO(stop, rc = 0);
+               }
 
                /* If the file type stored in the name entry does not match
                 * the file type claimed by the object, and the object does
                 * not recognize the name entry, then it is quite possible
                 * that the name entry is corrupted. */
                if ((lfsck_object_type(obj) & S_IFMT) != lnr->lnr_type) {
+                       ns->ln_flags |= LF_INCONSISTENT;
                        type = LNIT_BAD_DIRENT;
 
                        GOTO(stop, rc = 0);
@@ -3883,7 +5361,6 @@ again:
                        type = LNIT_BAD_TYPE;
 
                count = 1;
-               ns->ln_flags |= LF_INCONSISTENT;
                /* The magic crashed, we are not sure whether there are more
                 * corrupt data in the linkea, so remove all linkea entries. */
                remove = true;
@@ -3894,27 +5371,55 @@ again:
                        type = LNIT_BAD_TYPE;
 
                count = 1;
-               ns->ln_flags |= LF_UPGRADE;
                remove = false;
                newdata = true;
 
 nodata:
                if (bk->lb_param & LPF_DRYRUN) {
+                       if (rc == -ENODATA)
+                               ns->ln_flags |= LF_UPGRADE;
+                       else
+                               ns->ln_flags |= LF_INCONSISTENT;
                        ns->ln_linkea_repaired++;
                        repaired = true;
                        log = true;
-                       goto record;
+                       goto stop;
                }
 
-               if (!lustre_handle_is_used(&lh))
+               if (!lustre_handle_is_used(&lh)) {
+                       remove = false;
+                       newdata = false;
+                       type = LNIT_NONE;
+
                        goto again;
+               }
+
+               LASSERT(handle != NULL);
+
+               if (dir == NULL) {
+                       dir = lfsck_assistant_object_load(env, lfsck, lso);
+                       if (IS_ERR(dir)) {
+                               rc = PTR_ERR(dir);
+
+                               GOTO(stop, rc == -ENOENT ? 0 : rc);
+                       }
+               }
+
+               rc = lfsck_namespace_check_exist(env, dir, obj, lnr->lnr_name);
+               if (rc != 0)
+                       GOTO(stop, rc);
+
+               bad_linkea = true;
+               if (!remove && newdata)
+                       ns->ln_flags |= LF_UPGRADE;
+               else if (remove || !(ns->ln_flags & LF_UPGRADE))
+                       ns->ln_flags |= LF_INCONSISTENT;
 
                if (remove) {
                        LASSERT(newdata);
 
-                       rc = dt_xattr_del(env, obj, XATTR_NAME_LINK, handle,
-                                         BYPASS_CAPA);
-                       if (rc != 0)
+                       rc = dt_xattr_del(env, obj, XATTR_NAME_LINK, handle);
+                       if (rc != 0 && rc != -ENOENT && rc != -ENODATA)
                                GOTO(stop, rc);
                }
 
@@ -3926,10 +5431,8 @@ nodata:
                }
 
                rc = linkea_add_buf(&ldata, cname, pfid);
-               if (rc != 0)
-                       GOTO(stop, rc);
-
-               rc = lfsck_links_write(env, obj, &ldata, handle);
+               if (rc == 0)
+                       rc = lfsck_links_write(env, obj, &ldata, handle);
                if (rc != 0)
                        GOTO(stop, rc);
 
@@ -3944,35 +5447,6 @@ nodata:
                GOTO(stop, rc);
        }
 
-record:
-       LASSERT(count > 0);
-
-       rc = dt_attr_get(env, obj, la, BYPASS_CAPA);
-       if (rc != 0)
-               GOTO(stop, rc);
-
-       if ((count == 1 && la->la_nlink == 1) ||
-           S_ISDIR(lfsck_object_type(obj)))
-               /* Usually, it is for single linked object or dir, do nothing.*/
-               GOTO(stop, rc);
-
-       /* Following modification will be in another transaction.  */
-       if (handle != NULL) {
-               dt_write_unlock(env, obj);
-               dtlocked = false;
-
-               dt_trans_stop(env, dev, handle);
-               handle = NULL;
-
-               lfsck_ibits_unlock(&lh, LCK_EX);
-       }
-
-       ns->ln_mul_linked_checked++;
-       rc = lfsck_namespace_trace_update(env, com, &lnr->lnr_fid,
-                                         LNTF_CHECK_LINKEA, true);
-
-       GOTO(out, rc);
-
 stop:
        if (dtlocked)
                dt_write_unlock(env, obj);
@@ -3983,7 +5457,38 @@ stop:
 out:
        lfsck_ibits_unlock(&lh, LCK_EX);
 
+       if (!name_is_dot_or_dotdot(lnr->lnr_name, lnr->lnr_namelen) &&
+           !lfsck_is_valid_slave_name_entry(env, lnr->lnr_lmv,
+                                            lnr->lnr_name, lnr->lnr_namelen) &&
+           type != LNIT_BAD_DIRENT) {
+               ns->ln_flags |= LF_INCONSISTENT;
+
+               log = false;
+               if (dir == NULL) {
+                       dir = lfsck_assistant_object_load(env, lfsck, lso);
+                       if (IS_ERR(dir)) {
+                               rc = PTR_ERR(dir);
+
+                               GOTO(trace, rc == -ENOENT ? 0 : rc);
+                       }
+               }
+
+               rc = lfsck_namespace_repair_bad_name_hash(env, com, dir,
+                                               lnr->lnr_lmv, lnr->lnr_name);
+               if (rc == 0)
+                       bad_hash = true;
+       }
+
        if (rc >= 0) {
+               if (type != LNIT_NONE && dir == NULL) {
+                       dir = lfsck_assistant_object_load(env, lfsck, lso);
+                       if (IS_ERR(dir)) {
+                               rc = PTR_ERR(dir);
+
+                               GOTO(trace, rc == -ENOENT ? 0 : rc);
+                       }
+               }
+
                switch (type) {
                case LNIT_BAD_TYPE:
                        log = false;
@@ -4008,69 +5513,555 @@ out:
                default:
                        break;
                }
+
+               if (obj != NULL && count == 1 &&
+                   S_ISREG(lfsck_object_type(obj)))
+                       dt_attr_get(env, obj, la);
+       }
+
+trace:
+       down_write(&com->lc_sem);
+       if (rc < 0) {
+               CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant fail to handle "
+                      "the entry: "DFID", parent "DFID", name %.*s: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), PFID(&lnr->lnr_fid), PFID(pfid),
+                      lnr->lnr_namelen, lnr->lnr_name, rc);
+
+               lfsck_namespace_record_failure(env, lfsck, ns);
+               if ((rc == -ENOTCONN || rc == -ESHUTDOWN || rc == -EREMCHG ||
+                    rc == -ETIMEDOUT || rc == -EHOSTDOWN ||
+                    rc == -EHOSTUNREACH || rc == -EINPROGRESS) &&
+                   dev != NULL && dev != lfsck->li_bottom)
+                       lfsck_lad_set_bitmap(env, com, idx);
+
+               if (!(bk->lb_param & LPF_FAILOUT))
+                       rc = 0;
+       } else {
+               if (repaired) {
+                       ns->ln_items_repaired++;
+                       if (log)
+                               CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant "
+                                      "repaired the entry: "DFID", parent "DFID
+                                      ", name %.*s, type %d\n",
+                                      lfsck_lfsck2name(lfsck),
+                                      PFID(&lnr->lnr_fid), PFID(pfid),
+                                      lnr->lnr_namelen, lnr->lnr_name, type);
+
+                       switch (type) {
+                       case LNIT_DANGLING:
+                               ns->ln_dangling_repaired++;
+                               break;
+                       case LNIT_BAD_TYPE:
+                               ns->ln_bad_type_repaired++;
+                               break;
+                       case LNIT_BAD_DIRENT:
+                               ns->ln_dirent_repaired++;
+                               break;
+                       default:
+                               break;
+                       }
+
+                       if (bk->lb_param & LPF_DRYRUN &&
+                           lfsck_pos_is_zero(&ns->ln_pos_first_inconsistent))
+                               lfsck_pos_fill(env, lfsck,
+                                              &ns->ln_pos_first_inconsistent,
+                                              false);
+               }
+
+               if (bad_hash) {
+                       ns->ln_name_hash_repaired++;
+
+                       /* Not count repeatedly. */
+                       if (!repaired) {
+                               ns->ln_items_repaired++;
+                               if (log)
+                                       CDEBUG(D_LFSCK, "%s: namespace LFSCK "
+                                              "assistant repaired the entry: "
+                                              DFID", parent "DFID
+                                              ", name %.*s\n",
+                                              lfsck_lfsck2name(lfsck),
+                                              PFID(&lnr->lnr_fid), PFID(pfid),
+                                              lnr->lnr_namelen, lnr->lnr_name);
+                       }
+
+                       if (bk->lb_param & LPF_DRYRUN &&
+                           lfsck_pos_is_zero(&ns->ln_pos_first_inconsistent))
+                               lfsck_pos_fill(env, lfsck,
+                                              &ns->ln_pos_first_inconsistent,
+                                              false);
+               }
+
+               rc = 0;
        }
 
-       down_write(&com->lc_sem);
-       if (rc < 0) {
-               CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant fail to handle "
-                      "the entry: "DFID", parent "DFID", name %.*s: rc = %d\n",
-                      lfsck_lfsck2name(lfsck), PFID(&lnr->lnr_fid),
-                      PFID(lfsck_dto2fid(lnr->lnr_obj)),
-                      lnr->lnr_namelen, lnr->lnr_name, rc);
+       if (count > 1 || la->la_nlink > 1)
+               ns->ln_mul_linked_checked++;
+
+       up_write(&com->lc_sem);
+
+       if (obj != NULL && !IS_ERR(obj))
+               lfsck_object_put(env, obj);
+
+       if (dir != NULL && !IS_ERR(dir))
+               lfsck_object_put(env, dir);
+
+       lad->lad_advance_lock = bad_linkea;
+
+       return rc;
+}
+
+/**
+ * Handle one orphan under the backend /lost+found directory
+ *
+ * Insert the orphan FID into the namespace LFSCK trace file for further
+ * processing (via the subsequent namespace LFSCK second-stage scanning).
+ * At the same time, remove the orphan name entry from backend /lost+found
+ * directory. There is an interval between the orphan name entry removed
+ * from the backend /lost+found directory and the orphan FID in the LFSCK
+ * trace file handled. In such interval, the LFSCK can be reset, then
+ * all the FIDs recorded in the namespace LFSCK trace file will be dropped.
+ * To guarantee that the orphans can be found when LFSCK run next time
+ * without e2fsck again, when remove the orphan name entry, the LFSCK
+ * will set the orphan's ctime attribute as 1. Since normal applications
+ * cannot change the object's ctime attribute as 1. Then when LFSCK run
+ * next time, it can record the object (that ctime is 1) in the namespace
+ * LFSCK trace file during the first-stage scanning.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] parent   pointer to the object for the backend /lost+found
+ * \param[in] ent      pointer to the name entry for the target under the
+ *                     backend /lost+found
+ *
+ * \retval             positive for repaired
+ * \retval             0 if needs to repair nothing
+ * \retval             negative error number on failure
+ */
+static int lfsck_namespace_scan_local_lpf_one(const struct lu_env *env,
+                                             struct lfsck_component *com,
+                                             struct dt_object *parent,
+                                             struct lu_dirent *ent)
+{
+       struct lfsck_thread_info        *info   = lfsck_env_info(env);
+       struct lu_fid                   *key    = &info->lti_fid;
+       struct lu_attr                  *la     = &info->lti_la;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct dt_object                *obj;
+       struct dt_device                *dev    = lfsck->li_bottom;
+       struct dt_object                *child  = NULL;
+       struct thandle                  *th     = NULL;
+       int                              idx;
+       int                              rc     = 0;
+       __u8                             flags  = 0;
+       bool                             exist  = false;
+       ENTRY;
+
+       child = lfsck_object_find_by_dev(env, dev, &ent->lde_fid);
+       if (IS_ERR(child))
+               RETURN(PTR_ERR(child));
+
+       LASSERT(dt_object_exists(child));
+       LASSERT(!dt_object_remote(child));
+
+       idx = lfsck_sub_trace_file_fid2idx(&ent->lde_fid);
+       obj = com->lc_sub_trace_objs[idx].lsto_obj;
+       fid_cpu_to_be(key, &ent->lde_fid);
+       rc = dt_lookup(env, obj, (struct dt_rec *)&flags,
+                      (const struct dt_key *)key);
+       if (rc == 0) {
+               exist = true;
+               flags |= LNTF_CHECK_ORPHAN;
+       } else if (rc == -ENOENT) {
+               flags = LNTF_CHECK_ORPHAN;
+       } else {
+               GOTO(out, rc);
+       }
+
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(out, rc = PTR_ERR(th));
+
+       /* a1. remove name entry from backend /lost+found */
+       rc = dt_declare_delete(env, parent,
+                              (const struct dt_key *)ent->lde_name, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       if (S_ISDIR(lfsck_object_type(child))) {
+               /* a2. decrease parent's nlink */
+               rc = dt_declare_ref_del(env, parent, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       }
+
+       if (exist) {
+               /* a3. remove child's FID from the LFSCK trace file. */
+               rc = dt_declare_delete(env, obj,
+                                      (const struct dt_key *)key, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       } else {
+               /* a4. set child's ctime as 1 */
+               memset(la, 0, sizeof(*la));
+               la->la_ctime = 1;
+               la->la_valid = LA_CTIME;
+               rc = dt_declare_attr_set(env, child, la, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       }
+
+       /* a5. insert child's FID into the LFSCK trace file. */
+       rc = dt_declare_insert(env, obj, (const struct dt_rec *)&flags,
+                              (const struct dt_key *)key, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       /* b1. remove name entry from backend /lost+found */
+       rc = dt_delete(env, parent, (const struct dt_key *)ent->lde_name, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       if (S_ISDIR(lfsck_object_type(child))) {
+               /* b2. decrease parent's nlink */
+               dt_write_lock(env, parent, 0);
+               rc = dt_ref_del(env, parent, th);
+               dt_write_unlock(env, parent);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       }
+
+       if (exist) {
+               /* a3. remove child's FID from the LFSCK trace file. */
+               rc = dt_delete(env, obj, (const struct dt_key *)key, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       } else {
+               /* b4. set child's ctime as 1 */
+               rc = dt_attr_set(env, child, la, th);
+               if (rc != 0)
+                       GOTO(stop, rc);
+       }
+
+       /* b5. insert child's FID into the LFSCK trace file. */
+       rc = dt_insert(env, obj, (const struct dt_rec *)&flags,
+                      (const struct dt_key *)key, th, 1);
+
+       GOTO(stop, rc = (rc == 0 ? 1 : rc));
+
+stop:
+       dt_trans_stop(env, dev, th);
+
+out:
+       lfsck_object_put(env, child);
+
+       return rc;
+}
+
+/**
+ * Handle orphans under the backend /lost+found directory
+ *
+ * Some backend checker, such as e2fsck for ldiskfs may find some orphans
+ * and put them under the backend /lost+found directory that is invisible
+ * to client. The LFSCK will scan such directory, for the original client
+ * visible orphans, add their fids into the namespace LFSCK trace file,
+ * then the subsenquent namespace LFSCK second-stage scanning can handle
+ * them as other objects to be double scanned: either move back to normal
+ * namespace, or to the global visible orphan directory:
+ * /ROOT/.lustre/lost+found/MDTxxxx/
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ */
+static void lfsck_namespace_scan_local_lpf(const struct lu_env *env,
+                                          struct lfsck_component *com)
+{
+       struct lfsck_thread_info        *info   = lfsck_env_info(env);
+       struct lu_dirent                *ent    =
+                                       (struct lu_dirent *)info->lti_key;
+       struct lu_seq_range             *range  = &info->lti_range;
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct ptlrpc_thread            *thread = &lfsck->li_thread;
+       struct lfsck_bookmark           *bk     = &lfsck->li_bookmark_ram;
+       struct lfsck_namespace          *ns     = com->lc_file_ram;
+       struct dt_object                *parent;
+       const struct dt_it_ops          *iops;
+       struct dt_it                    *di;
+       struct seq_server_site          *ss     = lfsck_dev_site(lfsck);
+       __u64                            cookie;
+       __u32                            idx    = lfsck_dev_idx(lfsck);
+       int                              rc     = 0;
+       __u16                            type;
+       ENTRY;
+
+       parent = lfsck_object_find_by_dev(env, lfsck->li_bottom,
+                                         &LU_BACKEND_LPF_FID);
+       if (IS_ERR(parent)) {
+               CERROR("%s: fail to find backend /lost+found: rc = %ld\n",
+                      lfsck_lfsck2name(lfsck), PTR_ERR(parent));
+               RETURN_EXIT;
+       }
+
+       /* It is normal that the /lost+found does not exist for ZFS backend. */
+       if (!dt_object_exists(parent))
+               GOTO(out, rc = 0);
+
+       if (unlikely(!dt_try_as_dir(env, parent)))
+               GOTO(out, rc = -ENOTDIR);
+
+       CDEBUG(D_LFSCK, "%s: start to scan backend /lost+found\n",
+              lfsck_lfsck2name(lfsck));
+
+       com->lc_new_scanned = 0;
+       iops = &parent->do_index_ops->dio_it;
+       di = iops->init(env, parent, LUDA_64BITHASH | LUDA_TYPE);
+       if (IS_ERR(di))
+               GOTO(out, rc = PTR_ERR(di));
+
+       rc = iops->load(env, di, 0);
+       if (rc == 0)
+               rc = iops->next(env, di);
+       else if (rc > 0)
+               rc = 0;
+
+       while (rc == 0) {
+               if (CFS_FAIL_TIMEOUT(OBD_FAIL_LFSCK_DELAY3, cfs_fail_val) &&
+                   unlikely(!thread_is_running(thread)))
+                       break;
+
+               rc = iops->rec(env, di, (struct dt_rec *)ent,
+                              LUDA_64BITHASH | LUDA_TYPE);
+               if (rc == 0)
+                       rc = lfsck_unpack_ent(ent, &cookie, &type);
+
+               if (unlikely(rc != 0)) {
+                       CDEBUG(D_LFSCK, "%s: fail to iterate backend "
+                              "/lost+found: rc = %d\n",
+                              lfsck_lfsck2name(lfsck), rc);
+
+                       goto skip;
+               }
+
+               /* skip dot and dotdot entries */
+               if (name_is_dot_or_dotdot(ent->lde_name, ent->lde_namelen))
+                       goto next;
+
+               if (!fid_seq_in_fldb(fid_seq(&ent->lde_fid)))
+                       goto skip;
+
+               if (fid_is_norm(&ent->lde_fid)) {
+                       fld_range_set_mdt(range);
+                       rc = fld_local_lookup(env, ss->ss_server_fld,
+                                             fid_seq(&ent->lde_fid), range);
+                       if (rc != 0)
+                               goto skip;
+               } else if (idx != 0) {
+                       /* If the returned FID is IGIF, then there are three
+                        * possible cases:
+                        *
+                        * 1) The object is upgraded from old Lustre-1.8 with
+                        *    IGIF assigned to such object.
+                        * 2) The object is a backend local object and is
+                        *    invisible to client.
+                        * 3) The object lost its LMV EA, and since there is
+                        *    no FID-in-dirent for the orphan in the backend
+                        *    /lost+found directory, then the low layer will
+                        *    return IGIF for such object.
+                        *
+                        * For MDTx (x != 0), it is either case 2) or case 3),
+                        * but from the LFSCK view, they are indistinguishable.
+                        * To be safe, the LFSCK will keep it there and report
+                        * some message, then the adminstrator can handle that
+                        * furtherly.
+                        *
+                        * For MDT0, it is more possible the case 1). The LFSCK
+                        * will handle the orphan as an upgraded object. */
+                       CDEBUG(D_LFSCK, "%s: the orphan %.*s with IGIF "DFID
+                              "in the backend /lost+found on the MDT %04x, "
+                              "to be safe, skip it.\n",
+                              lfsck_lfsck2name(lfsck), ent->lde_namelen,
+                              ent->lde_name, PFID(&ent->lde_fid), idx);
+                       goto skip;
+               }
+
+               rc = lfsck_namespace_scan_local_lpf_one(env, com, parent, ent);
+
+skip:
+               down_write(&com->lc_sem);
+               com->lc_new_scanned++;
+               ns->ln_local_lpf_scanned++;
+               if (rc > 0)
+                       ns->ln_local_lpf_moved++;
+               else if (rc == 0)
+                       ns->ln_local_lpf_skipped++;
+               else
+                       ns->ln_local_lpf_failed++;
+               up_write(&com->lc_sem);
+
+               if (rc < 0 && bk->lb_param & LPF_FAILOUT)
+                       break;
+
+next:
+               lfsck_control_speed_by_self(com);
+               if (unlikely(!thread_is_running(thread))) {
+                       rc = 0;
+                       break;
+               }
+
+               rc = iops->next(env, di);
+       }
+
+       iops->put(env, di);
+       iops->fini(env, di);
+
+       EXIT;
+
+out:
+       CDEBUG(D_LFSCK, "%s: stop to scan backend /lost+found: rc = %d\n",
+              lfsck_lfsck2name(lfsck), rc);
+
+       lfsck_object_put(env, parent);
+}
+
+/**
+ * Rescan the striped directory after the master LMV EA reset.
+ *
+ * Sometimes, the master LMV EA of the striped directory maybe lost, so when
+ * the namespace LFSCK engine scan the striped directory for the first time,
+ * it will be regarded as a normal directory. As the LFSCK processing, some
+ * other LFSCK instance on other MDT will find the shard of this striped dir,
+ * and find that the master MDT-object of the striped directory lost its LMV
+ * EA, then such remote LFSCK instance will regenerate the master LMV EA and
+ * notify the LFSCK instance on this MDT to rescan the striped directory.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] llu      the lfsck_lmv_unit that contains the striped directory
+ *                     to be rescanned.
+ *
+ * \retval             positive number for success
+ * \retval             0 for LFSCK stopped/paused
+ * \retval             negative error number on failure
+ */
+static int lfsck_namespace_rescan_striped_dir(const struct lu_env *env,
+                                             struct lfsck_component *com,
+                                             struct lfsck_lmv_unit *llu)
+{
+       struct lfsck_thread_info        *info   = lfsck_env_info(env);
+       struct lfsck_instance           *lfsck  = com->lc_lfsck;
+       struct lfsck_assistant_data     *lad    = com->lc_data;
+       struct dt_object                *dir;
+       const struct dt_it_ops          *iops;
+       struct dt_it                    *di;
+       struct lu_dirent                *ent    =
+                       (struct lu_dirent *)info->lti_key;
+       struct lfsck_bookmark           *bk     = &lfsck->li_bookmark_ram;
+       struct ptlrpc_thread            *thread = &lfsck->li_thread;
+       struct lfsck_assistant_object   *lso    = NULL;
+       struct lfsck_namespace_req      *lnr;
+       struct lfsck_assistant_req      *lar;
+       int                              rc;
+       __u16                            type;
+       ENTRY;
+
+       LASSERT(list_empty(&lad->lad_req_list));
 
-               lfsck_namespace_record_failure(env, lfsck, ns);
-               if (!(bk->lb_param & LPF_FAILOUT))
-                       rc = 0;
-       } else {
-               if (log)
-                       CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant "
-                              "repaired the entry: "DFID", parent "DFID
-                              ", name %.*s\n", lfsck_lfsck2name(lfsck),
-                              PFID(&lnr->lnr_fid),
-                              PFID(lfsck_dto2fid(lnr->lnr_obj)),
-                              lnr->lnr_namelen, lnr->lnr_name);
+       lfsck->li_lmv = &llu->llu_lmv;
+       lfsck->li_obj_dir = lfsck_object_get(llu->llu_obj);
+       rc = lfsck_open_dir(env, lfsck, 0);
+       if (rc != 0)
+               RETURN(rc);
 
-               if (repaired) {
-                       ns->ln_items_repaired++;
+       dir = lfsck->li_obj_dir;
+       di = lfsck->li_di_dir;
+       iops = &dir->do_index_ops->dio_it;
+       do {
+               rc = iops->rec(env, di, (struct dt_rec *)ent,
+                              lfsck->li_args_dir);
+               if (rc == 0)
+                       rc = lfsck_unpack_ent(ent, &lfsck->li_cookie_dir,
+                                             &type);
 
-                       switch (type) {
-                       case LNIT_DANGLING:
-                               ns->ln_dangling_repaired++;
-                               break;
-                       case LNIT_BAD_TYPE:
-                               ns->ln_bad_type_repaired++;
-                               break;
-                       case LNIT_BAD_DIRENT:
-                               ns->ln_dirent_repaired++;
-                               break;
-                       default:
-                               break;
+               if (rc != 0) {
+                       if (bk->lb_param & LPF_FAILOUT)
+                               GOTO(out, rc);
+
+                       goto next;
+               }
+
+               if (name_is_dot_or_dotdot(ent->lde_name, ent->lde_namelen))
+                       goto next;
+
+               if (lso == NULL) {
+                       lso = lfsck_assistant_object_init(env,
+                               lfsck_dto2fid(dir), NULL,
+                               lfsck->li_pos_current.lp_oit_cookie, true);
+                       if (IS_ERR(lso)) {
+                               if (bk->lb_param & LPF_FAILOUT)
+                                       GOTO(out, rc = PTR_ERR(lso));
+
+                               lso = NULL;
+                               goto next;
                        }
+               }
 
-                       if (bk->lb_param & LPF_DRYRUN &&
-                           lfsck_pos_is_zero(&ns->ln_pos_first_inconsistent))
-                               lfsck_pos_fill(env, lfsck,
-                                              &ns->ln_pos_first_inconsistent,
-                                              false);
+               lnr = lfsck_namespace_assistant_req_init(lfsck, lso, ent, type);
+               if (IS_ERR(lnr)) {
+                       if (bk->lb_param & LPF_FAILOUT)
+                               GOTO(out, rc = PTR_ERR(lnr));
+
+                       goto next;
                }
 
-               rc = 0;
-       }
-       up_write(&com->lc_sem);
+               lar = &lnr->lnr_lar;
+               rc = lfsck_namespace_assistant_handler_p1(env, com, lar);
+               lfsck_namespace_assistant_req_fini(env, lar);
+               if (rc != 0 && bk->lb_param & LPF_FAILOUT)
+                       GOTO(out, rc);
 
-       if (obj != NULL && !IS_ERR(obj))
-               lfsck_object_put(env, obj);
-       return rc;
+               if (unlikely(!thread_is_running(thread)))
+                       GOTO(out, rc = 0);
+
+next:
+               rc = iops->next(env, di);
+       } while (rc == 0);
+
+out:
+       if (lso != NULL && !IS_ERR(lso))
+               lfsck_assistant_object_put(env, lso);
+
+       lfsck_close_dir(env, lfsck, rc);
+       if (rc <= 0)
+               RETURN(rc);
+
+       /* The close_dir() may insert a dummy lnr in the lad->lad_req_list. */
+       if (list_empty(&lad->lad_req_list))
+               RETURN(1);
+
+       spin_lock(&lad->lad_lock);
+       lar = list_entry(lad->lad_req_list.next, struct lfsck_assistant_req,
+                         lar_list);
+       list_del_init(&lar->lar_list);
+       spin_unlock(&lad->lad_lock);
+
+       rc = lfsck_namespace_assistant_handler_p1(env, com, lar);
+       lfsck_namespace_assistant_req_fini(env, lar);
+
+       RETURN(rc == 0 ? 1 : rc);
 }
 
-static int lfsck_namespace_assistant_handler_p2(const struct lu_env *env,
-                                               struct lfsck_component *com)
+static int
+lfsck_namespace_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_namespace  *ns     = com->lc_file_ram;
-       struct dt_object        *obj    = com->lc_obj;
        const struct dt_it_ops  *iops   = &obj->do_index_ops->dio_it;
        struct dt_object        *target;
        struct dt_it            *di;
@@ -4080,52 +6071,47 @@ static int lfsck_namespace_assistant_handler_p2(const struct lu_env *env,
        __u8                     flags  = 0;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "%s: namespace LFSCK 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();
-       com->lc_time_next_checkpoint = com->lc_time_last_checkpoint +
-                               cfs_time_seconds(LFSCK_CHECKPOINT_INTERVAL);
-
-       di = iops->init(env, obj, 0, BYPASS_CAPA);
+       di = iops->init(env, obj, 0);
        if (IS_ERR(di))
                RETURN(PTR_ERR(di));
 
-       fid_cpu_to_be(&fid, &ns->ln_fid_latest_scanned_phase2);
+       if (first)
+               fid_cpu_to_be(&fid, &ns->ln_fid_latest_scanned_phase2);
+       else
+               fid_zero(&fid);
        rc = iops->get(env, di, (const struct dt_key *)&fid);
        if (rc < 0)
                GOTO(fini, rc);
 
-       /* Skip the start one, which either has been processed or non-exist. */
-       rc = iops->next(env, di);
-       if (rc != 0)
-               GOTO(put, 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 (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_DELAY3) &&
-                   cfs_fail_val > 0) {
-                       struct l_wait_info lwi;
-
-                       lwi = LWI_TIMEOUT(cfs_time_seconds(cfs_fail_val),
-                                         NULL, NULL);
-                       l_wait_event(thread->t_ctl_waitq,
-                                    !thread_is_running(thread),
-                                    &lwi);
-
-                       if (unlikely(!thread_is_running(thread)))
-                               GOTO(put, rc = 0);
-               }
+               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(&fid, (const struct lu_fid *)key);
                if (!fid_is_sane(&fid)) {
                        rc = 0;
                        goto checkpoint;
                }
 
-               target = lfsck_object_find(env, lfsck, &fid);
+               target = lfsck_object_find_bottom(env, lfsck, &fid);
                if (IS_ERR(target)) {
                        rc = PTR_ERR(target);
                        goto checkpoint;
@@ -4147,7 +6133,9 @@ checkpoint:
                down_write(&com->lc_sem);
                com->lc_new_checked++;
                com->lc_new_scanned++;
-               ns->ln_fid_latest_scanned_phase2 = fid;
+               if (rc >= 0)
+                       ns->ln_fid_latest_scanned_phase2 = fid;
+
                if (rc > 0)
                        ns->ln_objs_repaired_phase2++;
                else if (rc < 0)
@@ -4167,10 +6155,8 @@ checkpoint:
                        ns->ln_time_last_checkpoint = cfs_time_current_sec();
                        ns->ln_objs_checked_phase2 += com->lc_new_checked;
                        com->lc_new_checked = 0;
-                       rc = lfsck_namespace_store(env, com, false);
+                       lfsck_namespace_store(env, com);
                        up_write(&com->lc_sem);
-                       if (rc != 0)
-                               GOTO(put, rc);
 
                        com->lc_time_last_checkpoint = cfs_time_current();
                        com->lc_time_next_checkpoint =
@@ -4193,12 +6179,56 @@ put:
 fini:
        iops->fini(env, di);
 
-       CDEBUG(D_LFSCK, "%s: namespace LFSCK phase2 scan stop: rc = %d\n",
-              lfsck_lfsck2name(lfsck), rc);
-
        return rc;
 }
 
+static int lfsck_namespace_assistant_handler_p2(const struct lu_env *env,
+                                               struct lfsck_component *com)
+{
+       struct lfsck_instance   *lfsck  = com->lc_lfsck;
+       struct lfsck_namespace  *ns     = com->lc_file_ram;
+       int                      rc;
+       int                      i;
+       ENTRY;
+
+       while (!list_empty(&lfsck->li_list_lmv)) {
+               struct lfsck_lmv_unit *llu;
+
+               spin_lock(&lfsck->li_lock);
+               llu = list_entry(lfsck->li_list_lmv.next,
+                                struct lfsck_lmv_unit, llu_link);
+               list_del_init(&llu->llu_link);
+               spin_unlock(&lfsck->li_lock);
+
+               rc = lfsck_namespace_rescan_striped_dir(env, com, llu);
+               if (rc <= 0)
+                       RETURN(rc);
+       }
+
+       CDEBUG(D_LFSCK, "%s: namespace LFSCK phase2 scan start\n",
+              lfsck_lfsck2name(lfsck));
+
+       lfsck_namespace_scan_local_lpf(env, com);
+
+       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(&ns->ln_fid_latest_scanned_phase2);
+       rc = lfsck_namespace_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_namespace_double_scan_one_trace_file(env, com,
+                               com->lc_sub_trace_objs[i].lsto_obj, false);
+
+       CDEBUG(D_LFSCK, "%s: namespace LFSCK phase2 scan stop at the No. %d "
+              "trace file: rc = %d\n", lfsck_lfsck2name(lfsck), i, rc);
+
+       RETURN(rc);
+}
+
 static void lfsck_namespace_assistant_fill_pos(const struct lu_env *env,
                                               struct lfsck_component *com,
                                               struct lfsck_position *pos)
@@ -4206,15 +6236,19 @@ static void lfsck_namespace_assistant_fill_pos(const struct lu_env *env,
        struct lfsck_assistant_data     *lad = com->lc_data;
        struct lfsck_namespace_req      *lnr;
 
+       if (((struct lfsck_namespace *)(com->lc_file_ram))->ln_status !=
+           LS_SCANNING_PHASE1)
+               return;
+
        if (list_empty(&lad->lad_req_list))
                return;
 
        lnr = list_entry(lad->lad_req_list.next,
                         struct lfsck_namespace_req,
                         lnr_lar.lar_list);
-       pos->lp_oit_cookie = lnr->lnr_oit_cookie;
+       pos->lp_oit_cookie = lnr->lnr_lar.lar_parent->lso_oit_cookie;
        pos->lp_dir_cookie = lnr->lnr_dir_cookie - 1;
-       pos->lp_dir_parent = *lfsck_dto2fid(lnr->lnr_obj);
+       pos->lp_dir_parent = lnr->lnr_lar.lar_parent->lso_fid;
 }
 
 static int lfsck_namespace_double_scan_result(const struct lu_env *env,
@@ -4226,7 +6260,7 @@ static int lfsck_namespace_double_scan_result(const struct lu_env *env,
 
        down_write(&com->lc_sem);
        ns->ln_run_time_phase2 += cfs_duration_sec(cfs_time_current() +
-                               HALF_SEC - lfsck->li_time_last_checkpoint);
+                                 HALF_SEC - com->lc_time_last_checkpoint);
        ns->ln_time_last_checkpoint = cfs_time_current_sec();
        ns->ln_objs_checked_phase2 += com->lc_new_checked;
        com->lc_new_checked = 0;
@@ -4241,24 +6275,112 @@ static int lfsck_namespace_double_scan_result(const struct lu_env *env,
                ns->ln_time_last_complete = ns->ln_time_last_checkpoint;
                ns->ln_success_count++;
        } else if (rc == 0) {
-               ns->ln_status = lfsck->li_status;
-               if (ns->ln_status == 0)
+               if (lfsck->li_status != 0)
+                       ns->ln_status = lfsck->li_status;
+               else
                        ns->ln_status = LS_STOPPED;
        } else {
                ns->ln_status = LS_FAILED;
        }
 
-       rc = lfsck_namespace_store(env, com, false);
+       rc = lfsck_namespace_store(env, com);
        up_write(&com->lc_sem);
 
        return rc;
 }
 
+static int
+lfsck_namespace_assistant_sync_failures_interpret(const struct lu_env *env,
+                                                 struct ptlrpc_request *req,
+                                                 void *args, int rc)
+{
+       if (rc == 0) {
+               struct lfsck_async_interpret_args *laia = args;
+               struct lfsck_tgt_desc             *ltd  = laia->laia_ltd;
+
+               ltd->ltd_synced_failures = 1;
+       }
+
+       return 0;
+}
+
+/**
+ * Notify remote LFSCK instances about former failures.
+ *
+ * The local LFSCK instance has recorded which MDTs have ever failed to respond
+ * some LFSCK verification requests (maybe because of network issues or the MDT
+ * itself trouble). During the respond gap the MDT may missed some name entries
+ * verification, then the MDT cannot know whether related MDT-objects have been
+ * referenced by related name entries or not, then in the second-stage scanning,
+ * these MDT-objects will be regarded as orphan, if the MDT-object contains bad
+ * linkEA for back reference, then it will misguide the LFSCK to generate wrong
+ * name entry for repairing the orphan.
+ *
+ * To avoid above trouble, when layout LFSCK finishes the first-stage scanning,
+ * it will scan the bitmap for the ever failed MDTs, and notify them that they
+ * have ever missed some name entries verification and should skip the handling
+ * for orphan MDT-objects.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] lr       pointer to the lfsck request
+ */
 static void lfsck_namespace_assistant_sync_failures(const struct lu_env *env,
                                                    struct lfsck_component *com,
                                                    struct lfsck_request *lr)
 {
-       /* XXX: TBD */
+       struct lfsck_async_interpret_args *laia  =
+                               &lfsck_env_info(env)->lti_laia2;
+       struct lfsck_assistant_data       *lad   = com->lc_data;
+       struct lfsck_namespace            *ns    = com->lc_file_ram;
+       struct lfsck_instance             *lfsck = com->lc_lfsck;
+       struct lfsck_tgt_descs            *ltds  = &lfsck->li_mdt_descs;
+       struct lfsck_tgt_desc             *ltd;
+       struct ptlrpc_request_set         *set;
+       __u32                              idx;
+       int                                rc    = 0;
+       ENTRY;
+
+       if (!lad->lad_incomplete)
+               RETURN_EXIT;
+
+       set = ptlrpc_prep_set();
+       if (set == NULL)
+               GOTO(out, rc = -ENOMEM);
+
+       lr->lr_flags2 = ns->ln_flags | LF_INCOMPLETE;
+       memset(laia, 0, sizeof(*laia));
+       lad->lad_touch_gen++;
+
+       down_read(&ltds->ltd_rw_sem);
+       cfs_foreach_bit(lad->lad_bitmap, idx) {
+               ltd = lfsck_ltd2tgt(ltds, idx);
+               LASSERT(ltd != NULL);
+
+               laia->laia_ltd = ltd;
+               rc = lfsck_async_request(env, ltd->ltd_exp, lr, set,
+                       lfsck_namespace_assistant_sync_failures_interpret,
+                       laia, LFSCK_NOTIFY);
+               if (rc != 0)
+                       CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant fail "
+                              "to sync failure with MDT %x: rc = %d\n",
+                              lfsck_lfsck2name(lfsck), ltd->ltd_index, rc);
+       }
+       up_read(&ltds->ltd_rw_sem);
+
+       rc = ptlrpc_set_wait(set);
+       ptlrpc_set_destroy(set);
+
+       GOTO(out, rc);
+
+out:
+       if (rc != 0)
+               CDEBUG(D_LFSCK, "%s: namespace LFSCK assistant fail "
+                      "to sync failure with MDTs, and related MDTs "
+                      "may handle orphan improperly: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), rc);
+
+       EXIT;
 }
 
 struct lfsck_assistant_operations lfsck_namespace_assistant_ops = {
@@ -4276,7 +6398,6 @@ struct lfsck_assistant_operations lfsck_namespace_assistant_ops = {
  * entries, then re-generate the linkEA with the given information.
  *
  * \param[in] env      pointer to the thread context
- * \param[in] dev      pointer to the dt_device
  * \param[in] obj      pointer to the dt_object to be handled
  * \param[in] cname    the name for the child in the parent directory
  * \param[in] pfid     the parent directory's FID for the linkEA
@@ -4284,11 +6405,11 @@ struct lfsck_assistant_operations lfsck_namespace_assistant_ops = {
  * \retval             0 for success
  * \retval             negative error number on failure
  */
-int lfsck_verify_linkea(const struct lu_env *env, struct dt_device *dev,
-                       struct dt_object *obj, const struct lu_name *cname,
-                       const struct lu_fid *pfid)
+int lfsck_verify_linkea(const struct lu_env *env, struct dt_object *obj,
+                       const struct lu_name *cname, const struct lu_fid *pfid)
 {
-       struct linkea_data       ldata  = { 0 };
+       struct dt_device        *dev    = lfsck_obj2dev(obj);
+       struct linkea_data       ldata  = { NULL };
        struct lu_buf            linkea_buf;
        struct thandle          *th;
        int                      rc;
@@ -4298,7 +6419,7 @@ int lfsck_verify_linkea(const struct lu_env *env, struct dt_device *dev,
 
        LASSERT(S_ISDIR(lfsck_object_type(obj)));
 
-       rc = lfsck_links_read(env, obj, &ldata);
+       rc = lfsck_links_read_with_rec(env, obj, &ldata);
        if (rc == -ENODATA) {
                dirty = true;
        } else if (rc == 0) {
@@ -4315,11 +6436,8 @@ int lfsck_verify_linkea(const struct lu_env *env, struct dt_device *dev,
        if (!dirty)
                RETURN(rc);
 
-       rc = linkea_data_new(&ldata, &lfsck_env_info(env)->lti_linkea_buf);
-       if (rc != 0)
-               RETURN(rc);
-
-       rc = linkea_add_buf(&ldata, cname, pfid);
+       rc = linkea_links_new(&ldata, &lfsck_env_info(env)->lti_linkea_buf,
+                             cname, pfid);
        if (rc != 0)
                RETURN(rc);
 
@@ -4340,7 +6458,7 @@ int lfsck_verify_linkea(const struct lu_env *env, struct dt_device *dev,
 
        dt_write_lock(env, obj, 0);
        rc = dt_xattr_set(env, obj, &linkea_buf,
-                         XATTR_NAME_LINK, fl, th, BYPASS_CAPA);
+                         XATTR_NAME_LINK, fl, th);
        dt_write_unlock(env, obj);
 
        GOTO(stop, rc);
@@ -4367,17 +6485,14 @@ int lfsck_links_get_first(const struct lu_env *env, struct dt_object *obj,
                          char *name, struct lu_fid *pfid)
 {
        struct lu_name           *cname = &lfsck_env_info(env)->lti_name;
-       struct linkea_data        ldata = { 0 };
+       struct linkea_data        ldata = { NULL };
        int                       rc;
 
-       rc = lfsck_links_read(env, obj, &ldata);
-       if (rc != 0)
+       rc = lfsck_links_read_with_rec(env, obj, &ldata);
+       if (rc)
                return rc;
 
        linkea_first_entry(&ldata);
-       if (ldata.ld_lee == NULL)
-               return -ENODATA;
-
        linkea_entry_unpack(ldata.ld_lee, &ldata.ld_reclen, cname, pfid);
        /* To guarantee the 'name' is terminated with '0'. */
        memcpy(name, cname->ln_name, cname->ln_namelen);
@@ -4387,90 +6502,14 @@ int lfsck_links_get_first(const struct lu_env *env, struct dt_object *obj,
 }
 
 /**
- * Remove the name entry from the parent directory.
- *
- * No need to care about the object referenced by the name entry,
- * either the name entry is invalid or redundant, or the referenced
- * object has been processed has been or will be handled by others.
- *
- * \param[in] env      pointer to the thread context
- * \param[in] lfsck    pointer to the lfsck instance
- * \param[in] parent   pointer to the lost+found object
- * \param[in] name     the name for the name entry to be removed
- * \param[in] type     the type for the name entry to be removed
- *
- * \retval             0 for success
- * \retval             negative error number on failure
- */
-int lfsck_remove_name_entry(const struct lu_env *env,
-                           struct lfsck_instance *lfsck,
-                           struct dt_object *parent,
-                           const char *name, __u32 type)
-{
-       struct dt_device        *dev    = lfsck->li_next;
-       struct thandle          *th;
-       struct lustre_handle     lh     = { 0 };
-       int                      rc;
-       ENTRY;
-
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
-       if (rc != 0)
-               RETURN(rc);
-
-       th = dt_trans_create(env, dev);
-       if (IS_ERR(th))
-               GOTO(unlock, rc = PTR_ERR(th));
-
-       rc = dt_declare_delete(env, parent, (const struct dt_key *)name, th);
-       if (rc != 0)
-               GOTO(stop, rc);
-
-       if (S_ISDIR(type)) {
-               rc = dt_declare_ref_del(env, parent, th);
-               if (rc != 0)
-                       GOTO(stop, rc);
-       }
-
-       rc = dt_trans_start(env, dev, th);
-       if (rc != 0)
-               GOTO(stop, rc);
-
-       rc = dt_delete(env, parent, (const struct dt_key *)name, th,
-                      BYPASS_CAPA);
-       if (rc != 0)
-               GOTO(stop, rc);
-
-       if (S_ISDIR(type)) {
-               dt_write_lock(env, parent, 0);
-               rc = dt_ref_del(env, parent, th);
-               dt_write_unlock(env, parent);
-       }
-
-       GOTO(stop, rc);
-
-stop:
-       dt_trans_stop(env, dev, th);
-
-unlock:
-       lfsck_ibits_unlock(&lh, LCK_EX);
-
-       CDEBUG(D_LFSCK, "%s: remove name entry "DFID"/%s "
-              "with type %o: rc = %d\n", lfsck_lfsck2name(lfsck),
-              PFID(lfsck_dto2fid(parent)), name, type, rc);
-
-       return rc;
-}
-
-/**
  * Update the object's name entry with the given FID.
  *
  * \param[in] env      pointer to the thread context
  * \param[in] lfsck    pointer to the lfsck instance
- * \param[in] parent   pointer to the parent directory that holds
+ * \param[in] dir      pointer to the directory that holds
  *                     the name entry
  * \param[in] name     the name for the entry to be updated
- * \param[in] pfid     the new PFID for the name entry
+ * \param[in] fid      the new FID for the name entry referenced
  * \param[in] type     the type for the name entry to be updated
  *
  * \retval             0 for success
@@ -4478,19 +6517,20 @@ unlock:
  */
 int lfsck_update_name_entry(const struct lu_env *env,
                            struct lfsck_instance *lfsck,
-                           struct dt_object *parent, const char *name,
-                           const struct lu_fid *pfid, __u32 type)
+                           struct dt_object *dir, const char *name,
+                           const struct lu_fid *fid, __u32 type)
 {
-       struct dt_insert_rec    *rec    = &lfsck_env_info(env)->lti_dt_rec;
-       struct dt_device        *dev    = lfsck->li_next;
-       struct lustre_handle     lh     = { 0 };
-       struct thandle          *th;
-       int                      rc;
-       bool                     exists = true;
+       struct lfsck_thread_info *info   = lfsck_env_info(env);
+       struct dt_insert_rec     *rec    = &info->lti_dt_rec;
+       struct lfsck_lock_handle *llh    = &info->lti_llh;
+       struct dt_device         *dev    = lfsck_obj2dev(dir);
+       struct thandle           *th;
+       int                       rc;
+       bool                      exists = true;
        ENTRY;
 
-       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
-                             MDS_INODELOCK_UPDATE, LCK_EX);
+       rc = lfsck_lock(env, lfsck, dir, name, llh,
+                       MDS_INODELOCK_UPDATE, LCK_PW);
        if (rc != 0)
                RETURN(rc);
 
@@ -4498,27 +6538,26 @@ int lfsck_update_name_entry(const struct lu_env *env,
        if (IS_ERR(th))
                GOTO(unlock, rc = PTR_ERR(th));
 
-       rc = dt_declare_delete(env, parent, (const struct dt_key *)name, th);
+       rc = dt_declare_delete(env, dir, (const struct dt_key *)name, th);
        if (rc != 0)
                GOTO(stop, rc);
 
        rec->rec_type = type;
-       rec->rec_fid = pfid;
-       rc = dt_declare_insert(env, parent, (const struct dt_rec *)rec,
+       rec->rec_fid = fid;
+       rc = dt_declare_insert(env, dir, (const struct dt_rec *)rec,
                               (const struct dt_key *)name, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_declare_ref_add(env, parent, th);
+       rc = dt_declare_ref_add(env, dir, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_trans_start(env, dev, th);
+       rc = dt_trans_start_local(env, dev, th);
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_delete(env, parent, (const struct dt_key *)name, th,
-                      BYPASS_CAPA);
+       rc = dt_delete(env, dir, (const struct dt_key *)name, th);
        if (rc == -ENOENT) {
                exists = false;
                rc = 0;
@@ -4527,12 +6566,12 @@ int lfsck_update_name_entry(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       rc = dt_insert(env, parent, (const struct dt_rec *)rec,
-                      (const struct dt_key *)name, th, BYPASS_CAPA, 1);
+       rc = dt_insert(env, dir, (const struct dt_rec *)rec,
+                      (const struct dt_key *)name, th, 1);
        if (rc == 0 && S_ISDIR(type) && !exists) {
-               dt_write_lock(env, parent, 0);
-               rc = dt_ref_add(env, parent, th);
-               dt_write_unlock(env, parent);
+               dt_write_lock(env, dir, 0);
+               rc = dt_ref_add(env, dir, th);
+               dt_write_unlock(env, dir);
        }
 
        GOTO(stop, rc);
@@ -4541,11 +6580,10 @@ stop:
        dt_trans_stop(env, dev, th);
 
 unlock:
-       lfsck_ibits_unlock(&lh, LCK_EX);
-
+       lfsck_unlock(llh);
        CDEBUG(D_LFSCK, "%s: update name entry "DFID"/%s with the FID "DFID
               " and the type %o: rc = %d\n", lfsck_lfsck2name(lfsck),
-              PFID(lfsck_dto2fid(parent)), name, PFID(pfid), type, rc);
+              PFID(lfsck_dto2fid(dir)), name, PFID(fid), type, rc);
 
        return rc;
 }
@@ -4557,6 +6595,7 @@ int lfsck_namespace_setup(const struct lu_env *env,
        struct lfsck_namespace  *ns;
        struct dt_object        *root = NULL;
        struct dt_object        *obj;
+       int                      i;
        int                      rc;
        ENTRY;
 
@@ -4575,7 +6614,7 @@ int lfsck_namespace_setup(const struct lu_env *env,
        com->lc_ops = &lfsck_namespace_ops;
        com->lc_data = lfsck_assistant_data_init(
                        &lfsck_namespace_assistant_ops,
-                       "lfsck_namespace");
+                       LFSCK_NAMESPACE);
        if (com->lc_data == NULL)
                GOTO(out, rc = -ENOMEM);
 
@@ -4588,6 +6627,9 @@ int lfsck_namespace_setup(const struct lu_env *env,
        if (com->lc_file_disk == NULL)
                GOTO(out, rc = -ENOMEM);
 
+       for (i = 0; i < LFSCK_STF_COUNT; i++)
+               mutex_init(&com->lc_sub_trace_objs[i].lsto_mutex);
+
        root = dt_locate(env, lfsck->li_bottom, &lfsck->li_local_root_fid);
        if (IS_ERR(root))
                GOTO(out, rc = PTR_ERR(root));
@@ -4596,22 +6638,21 @@ int lfsck_namespace_setup(const struct lu_env *env,
                GOTO(out, rc = -ENOTDIR);
 
        obj = local_index_find_or_create(env, lfsck->li_los, root,
-                                        lfsck_namespace_name,
+                                        LFSCK_NAMESPACE,
                                         S_IFREG | S_IRUGO | S_IWUSR,
-                                        &dt_lfsck_features);
+                                        &dt_lfsck_namespace_features);
        if (IS_ERR(obj))
                GOTO(out, rc = PTR_ERR(obj));
 
        com->lc_obj = obj;
-       rc = obj->do_ops->do_index_try(env, obj, &dt_lfsck_features);
-       if (rc != 0)
-               GOTO(out, rc);
-
        rc = lfsck_namespace_load(env, com);
-       if (rc > 0)
-               rc = lfsck_namespace_reset(env, com, true);
-       else if (rc == -ENODATA)
+       if (rc == -ENODATA)
                rc = lfsck_namespace_init(env, com);
+       else if (rc < 0)
+               rc = lfsck_namespace_reset(env, com, true);
+       else
+               rc = lfsck_load_sub_trace_files(env, com,
+                       &dt_lfsck_namespace_features, LFSCK_NAMESPACE, false);
        if (rc != 0)
                GOTO(out, rc);
 
@@ -4649,7 +6690,7 @@ int lfsck_namespace_setup(const struct lu_env *env,
 
 out:
        if (root != NULL && !IS_ERR(root))
-               lu_object_put(env, &root->do_lu);
+               lfsck_object_put(env, root);
        if (rc != 0) {
                lfsck_component_cleanup(env, com);
                CERROR("%s: fail to init namespace LFSCK component: rc = %d\n",