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LU-15727 lod: honor append_pool with default composite layouts
[fs/lustre-release.git] / lustre / lod / lod_object.c
index cd38047..a2d36fa 100644 (file)
@@ -98,9 +98,9 @@ static int lod_declare_insert(const struct lu_env *env, struct dt_object *dt,
  */
 static int lod_insert(const struct lu_env *env, struct dt_object *dt,
                      const struct dt_rec *rec, const struct dt_key *key,
-                     struct thandle *th, int ign)
+                     struct thandle *th)
 {
-       return lod_sub_insert(env, dt_object_child(dt), rec, key, th, ign);
+       return lod_sub_insert(env, dt_object_child(dt), rec, key, th);
 }
 
 /**
@@ -344,7 +344,7 @@ static int lod_it_key_rec(const struct lu_env *env, const struct dt_it *di,
                                                         key_rec);
 }
 
-static struct dt_index_operations lod_index_ops = {
+static const struct dt_index_operations lod_index_ops = {
        .dio_lookup             = lod_lookup,
        .dio_declare_insert     = lod_declare_insert,
        .dio_insert             = lod_insert,
@@ -367,6 +367,50 @@ static struct dt_index_operations lod_index_ops = {
 };
 
 /**
+ * Implementation of dt_index_operations::dio_lookup
+ *
+ * Used with striped directories.
+ *
+ * \see dt_index_operations::dio_lookup() in the API description for details.
+ */
+static int lod_striped_lookup(const struct lu_env *env, struct dt_object *dt,
+                     struct dt_rec *rec, const struct dt_key *key)
+{
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next;
+       const char *name = (const char *)key;
+
+       LASSERT(lo->ldo_dir_stripe_count > 0);
+
+       if (strcmp(name, dot) == 0) {
+               struct lu_fid *fid = (struct lu_fid *)rec;
+
+               *fid = *lod_object_fid(lo);
+               return 1;
+       }
+
+       if (strcmp(name, dotdot) == 0) {
+               next = dt_object_child(dt);
+       } else {
+               int index;
+
+               index = __lmv_name_to_stripe_index(lo->ldo_dir_hash_type,
+                                                  lo->ldo_dir_stripe_count,
+                                                  lo->ldo_dir_migrate_hash,
+                                                  lo->ldo_dir_migrate_offset,
+                                                  name, strlen(name), true);
+               if (index < 0)
+                       return index;
+
+               next = lo->ldo_stripe[index];
+               if (!next || !dt_object_exists(next))
+                       return -ENODEV;
+       }
+
+       return next->do_index_ops->dio_lookup(env, next, rec, key);
+}
+
+/**
  * Implementation of dt_it_ops::init.
  *
  * Used with striped objects. Internally just initializes the iterator
@@ -377,15 +421,24 @@ static struct dt_index_operations lod_index_ops = {
 static struct dt_it *lod_striped_it_init(const struct lu_env *env,
                                         struct dt_object *dt, __u32 attr)
 {
-       struct lod_object       *lo = lod_dt_obj(dt);
-       struct dt_object        *next;
-       struct lod_it           *it = &lod_env_info(env)->lti_it;
-       struct dt_it            *it_next;
-       ENTRY;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next;
+       struct lod_it *it = &lod_env_info(env)->lti_it;
+       struct dt_it *it_next;
+       __u16 index = 0;
 
        LASSERT(lo->ldo_dir_stripe_count > 0);
-       next = lo->ldo_stripe[0];
-       LASSERT(next != NULL);
+
+       do {
+               next = lo->ldo_stripe[index];
+               if (next && dt_object_exists(next))
+                       break;
+       } while (++index < lo->ldo_dir_stripe_count);
+
+       /* no valid stripe */
+       if (!next || !dt_object_exists(next))
+               return ERR_PTR(-ENODEV);
+
        LASSERT(next->do_index_ops != NULL);
 
        it_next = next->do_index_ops->dio_it.init(env, next, attr);
@@ -398,7 +451,7 @@ static struct dt_it *lod_striped_it_init(const struct lu_env *env,
         * additional ones */
        LASSERT(it->lit_obj == NULL);
 
-       it->lit_stripe_index = 0;
+       it->lit_stripe_index = index;
        it->lit_attr = attr;
        it->lit_it = it_next;
        it->lit_obj = dt;
@@ -433,10 +486,10 @@ static void lod_striped_it_fini(const struct lu_env *env, struct dt_it *di)
                LOD_CHECK_STRIPED_IT(env, it, lo);
 
                next = lo->ldo_stripe[it->lit_stripe_index];
-               LASSERT(next != NULL);
-               LASSERT(next->do_index_ops != NULL);
-
-               next->do_index_ops->dio_it.fini(env, it->lit_it);
+               if (next) {
+                       LASSERT(next->do_index_ops != NULL);
+                       next->do_index_ops->dio_it.fini(env, it->lit_it);
+               }
        }
 
        /* the iterator not in use any more */
@@ -457,15 +510,15 @@ static void lod_striped_it_fini(const struct lu_env *env, struct dt_it *di)
 static int lod_striped_it_get(const struct lu_env *env, struct dt_it *di,
                              const struct dt_key *key)
 {
-       const struct lod_it     *it = (const struct lod_it *)di;
-       struct lod_object       *lo = lod_dt_obj(it->lit_obj);
-       struct dt_object        *next;
-       ENTRY;
+       const struct lod_it *it = (const struct lod_it *)di;
+       struct lod_object *lo = lod_dt_obj(it->lit_obj);
+       struct dt_object *next;
 
        LOD_CHECK_STRIPED_IT(env, it, lo);
 
        next = lo->ldo_stripe[it->lit_stripe_index];
        LASSERT(next != NULL);
+       LASSERT(dt_object_exists(next));
        LASSERT(next->do_index_ops != NULL);
 
        return next->do_index_ops->dio_it.get(env, it->lit_it, key);
@@ -480,9 +533,16 @@ static int lod_striped_it_get(const struct lu_env *env, struct dt_it *di,
  */
 static void lod_striped_it_put(const struct lu_env *env, struct dt_it *di)
 {
-       struct lod_it           *it = (struct lod_it *)di;
-       struct lod_object       *lo = lod_dt_obj(it->lit_obj);
-       struct dt_object        *next;
+       struct lod_it *it = (struct lod_it *)di;
+       struct lod_object *lo = lod_dt_obj(it->lit_obj);
+       struct dt_object *next;
+
+       /*
+        * If lit_it == NULL, then it means the sub_it has been finished,
+        * which only happens in failure cases, see lod_striped_it_next()
+        */
+       if (!it->lit_it)
+               return;
 
        LOD_CHECK_STRIPED_IT(env, it, lo);
 
@@ -503,17 +563,20 @@ static void lod_striped_it_put(const struct lu_env *env, struct dt_it *di)
  */
 static int lod_striped_it_next(const struct lu_env *env, struct dt_it *di)
 {
-       struct lod_it           *it = (struct lod_it *)di;
-       struct lod_object       *lo = lod_dt_obj(it->lit_obj);
-       struct dt_object        *next;
-       struct dt_it            *it_next;
-       int                     rc;
+       struct lod_it *it = (struct lod_it *)di;
+       struct lod_object *lo = lod_dt_obj(it->lit_obj);
+       struct dt_object *next;
+       struct dt_it *it_next;
+       __u32 index;
+       int rc;
+
        ENTRY;
 
        LOD_CHECK_STRIPED_IT(env, it, lo);
 
        next = lo->ldo_stripe[it->lit_stripe_index];
        LASSERT(next != NULL);
+       LASSERT(dt_object_exists(next));
        LASSERT(next->do_index_ops != NULL);
 again:
        rc = next->do_index_ops->dio_it.next(env, it->lit_it);
@@ -546,33 +609,44 @@ again:
                RETURN(rc);
        }
 
-       /* go to next stripe */
-       if (it->lit_stripe_index + 1 >= lo->ldo_dir_stripe_count)
-               RETURN(1);
-
-       it->lit_stripe_index++;
-
        next->do_index_ops->dio_it.put(env, it->lit_it);
        next->do_index_ops->dio_it.fini(env, it->lit_it);
        it->lit_it = NULL;
 
-       next = lo->ldo_stripe[it->lit_stripe_index];
-       LASSERT(next != NULL);
-       rc = next->do_ops->do_index_try(env, next, &dt_directory_features);
-       if (rc != 0)
-               RETURN(rc);
+       /* go to next stripe */
+       index = it->lit_stripe_index;
+       while (++index < lo->ldo_dir_stripe_count) {
+               next = lo->ldo_stripe[index];
+               if (!next)
+                       continue;
 
-       LASSERT(next->do_index_ops != NULL);
+               if (!dt_object_exists(next))
+                       continue;
+
+               rc = next->do_ops->do_index_try(env, next,
+                                               &dt_directory_features);
+               if (rc != 0)
+                       RETURN(rc);
+
+               LASSERT(next->do_index_ops != NULL);
+
+               it_next = next->do_index_ops->dio_it.init(env, next,
+                                                         it->lit_attr);
+               if (IS_ERR(it_next))
+                       RETURN(PTR_ERR(it_next));
+
+               rc = next->do_index_ops->dio_it.get(env, it_next,
+                                                   (const struct dt_key *)"");
+               if (rc <= 0)
+                       RETURN(rc == 0 ? -EIO : rc);
 
-       it_next = next->do_index_ops->dio_it.init(env, next, it->lit_attr);
-       if (!IS_ERR(it_next)) {
                it->lit_it = it_next;
+               it->lit_stripe_index = index;
                goto again;
-       } else {
-               rc = PTR_ERR(it_next);
+
        }
 
-       RETURN(rc);
+       RETURN(1);
 }
 
 /**
@@ -713,8 +787,8 @@ static int lod_striped_it_load(const struct lu_env *env,
        return next->do_index_ops->dio_it.load(env, it->lit_it, hash);
 }
 
-static struct dt_index_operations lod_striped_index_ops = {
-       .dio_lookup             = lod_lookup,
+static const struct dt_index_operations lod_striped_index_ops = {
+       .dio_lookup             = lod_striped_lookup,
        .dio_declare_insert     = lod_declare_insert,
        .dio_insert             = lod_insert,
        .dio_declare_delete     = lod_declare_delete,
@@ -841,18 +915,17 @@ int lod_load_lmv_shards(const struct lu_env *env, struct lod_object *lo,
                                goto next;
                }
 
-               len = snprintf(name, sizeof(name),
-                              DFID":", PFID(&ent->lde_fid));
+               len = scnprintf(name, sizeof(name),
+                               DFID":", PFID(&ent->lde_fid));
                /* The ent->lde_name is composed of ${FID}:${index} */
                if (ent->lde_namelen < len + 1 ||
                    memcmp(ent->lde_name, name, len) != 0) {
-                       CDEBUG(lod->lod_lmv_failout ? D_ERROR : D_INFO,
-                              "%s: invalid shard name %.*s with the FID "DFID
-                              " for the striped directory "DFID", %s\n",
-                              lod2obd(lod)->obd_name, ent->lde_namelen,
-                              ent->lde_name, PFID(&fid),
-                              PFID(lu_object_fid(&obj->do_lu)),
-                              lod->lod_lmv_failout ? "failout" : "skip");
+                       CDEBUG_LIMIT(lod->lod_lmv_failout ? D_ERROR : D_INFO,
+                                    "%s: invalid shard name %.*s with the FID "DFID" for the striped directory "DFID", %s\n",
+                                    lod2obd(lod)->obd_name, ent->lde_namelen,
+                                    ent->lde_name, PFID(&fid),
+                                    PFID(lu_object_fid(&obj->do_lu)),
+                                    lod->lod_lmv_failout ? "failout" : "skip");
 
                        if (lod->lod_lmv_failout)
                                break;
@@ -864,15 +937,15 @@ int lod_load_lmv_shards(const struct lu_env *env, struct lod_object *lo,
                do {
                        if (ent->lde_name[len] < '0' ||
                            ent->lde_name[len] > '9') {
-                               CDEBUG(lod->lod_lmv_failout ? D_ERROR : D_INFO,
-                                      "%s: invalid shard name %.*s with the "
-                                      "FID "DFID" for the striped directory "
-                                      DFID", %s\n",
-                                      lod2obd(lod)->obd_name, ent->lde_namelen,
-                                      ent->lde_name, PFID(&fid),
-                                      PFID(lu_object_fid(&obj->do_lu)),
-                                      lod->lod_lmv_failout ?
-                                      "failout" : "skip");
+                               CDEBUG_LIMIT(lod->lod_lmv_failout ?
+                                            D_ERROR : D_INFO,
+                                            "%s: invalid shard name %.*s with the FID "DFID" for the striped directory "DFID", %s\n",
+                                            lod2obd(lod)->obd_name,
+                                            ent->lde_namelen,
+                                            ent->lde_name, PFID(&fid),
+                                            PFID(lu_object_fid(&obj->do_lu)),
+                                            lod->lod_lmv_failout ?
+                                            "failout" : "skip");
 
                                if (lod->lod_lmv_failout)
                                        break;
@@ -956,7 +1029,9 @@ static int lod_index_try(const struct lu_env *env, struct dt_object *dt,
                int i;
 
                for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-                       if (dt_object_exists(lo->ldo_stripe[i]) == 0)
+                       if (!lo->ldo_stripe[i])
+                               continue;
+                       if (!dt_object_exists(lo->ldo_stripe[i]))
                                continue;
                        rc = lo->ldo_stripe[i]->do_ops->do_index_try(env,
                                                lo->ldo_stripe[i], feat);
@@ -1043,16 +1118,57 @@ static int lod_attr_get(const struct lu_env *env,
        return dt_attr_get(env, dt_object_child(dt), attr);
 }
 
+void lod_adjust_stripe_size(struct lod_layout_component *comp,
+                           __u32 def_stripe_size)
+{
+       __u64 comp_end = comp->llc_extent.e_end;
+
+       /* Choose stripe size if not set. Note that default stripe size can't
+        * be used as is, because it must be multiplier of given component end.
+        *  - first check if default stripe size can be used
+        *  - if not than select the lowest set bit from component end and use
+        *    that value as stripe size
+        */
+       if (!comp->llc_stripe_size) {
+               if (comp_end == LUSTRE_EOF || !(comp_end % def_stripe_size))
+                       comp->llc_stripe_size = def_stripe_size;
+               else
+                       comp->llc_stripe_size = comp_end & ~(comp_end - 1);
+       } else {
+               if (comp_end != LUSTRE_EOF &&
+                   comp_end & (LOV_MIN_STRIPE_SIZE - 1)) {
+                       CWARN("Component end %llu is not a multiple of min size %u\n",
+                             comp_end, LOV_MIN_STRIPE_SIZE);
+                       comp_end = round_up(comp_end, LOV_MIN_STRIPE_SIZE);
+               }
+               /* check stripe size is multiplier of comp_end */
+               if (comp_end != LUSTRE_EOF &&
+                   comp_end != comp->llc_extent.e_start &&
+                   comp_end % comp->llc_stripe_size) {
+                       /* fix that even for defined stripe size but warn
+                        * about the problem, that must not happen
+                        */
+                       CWARN("Component end %llu is not aligned by the stripe size %u\n",
+                             comp_end, comp->llc_stripe_size);
+                       comp->llc_stripe_size = comp_end & ~(comp_end - 1);
+               }
+       }
+}
+
 static inline void lod_adjust_stripe_info(struct lod_layout_component *comp,
-                                         struct lov_desc *desc)
+                                         struct lov_desc *desc,
+                                         int append_stripes)
 {
        if (comp->llc_pattern != LOV_PATTERN_MDT) {
-               if (!comp->llc_stripe_count)
+               if (append_stripes) {
+                       comp->llc_stripe_count = append_stripes;
+               } else if (!comp->llc_stripe_count) {
                        comp->llc_stripe_count =
                                desc->ld_default_stripe_count;
+               }
        }
-       if (comp->llc_stripe_size <= 0)
-               comp->llc_stripe_size = desc->ld_default_stripe_size;
+
+       lod_adjust_stripe_size(comp, desc->ld_default_stripe_size);
 }
 
 int lod_obj_for_each_stripe(const struct lu_env *env, struct lod_object *lo,
@@ -1060,10 +1176,10 @@ int lod_obj_for_each_stripe(const struct lu_env *env, struct lod_object *lo,
                            struct lod_obj_stripe_cb_data *data)
 {
        struct lod_layout_component *lod_comp;
-       int i, j, rc;
+       int i, j, rc = 0;
        ENTRY;
 
-       LASSERT(lo->ldo_comp_cnt != 0 && lo->ldo_comp_entries != NULL);
+       mutex_lock(&lo->ldo_layout_mutex);
        for (i = 0; i < lo->ldo_comp_cnt; i++) {
                lod_comp = &lo->ldo_comp_entries[i];
 
@@ -1083,7 +1199,7 @@ int lod_obj_for_each_stripe(const struct lu_env *env, struct lod_object *lo,
                if (data->locd_comp_cb) {
                        rc = data->locd_comp_cb(env, lo, i, data);
                        if (rc)
-                               RETURN(rc);
+                               GOTO(unlock, rc);
                }
 
                /* could used just to do sth about component, not each
@@ -1100,10 +1216,12 @@ int lod_obj_for_each_stripe(const struct lu_env *env, struct lod_object *lo,
                                continue;
                        rc = data->locd_stripe_cb(env, lo, dt, th, i, j, data);
                        if (rc != 0)
-                               RETURN(rc);
+                               GOTO(unlock, rc);
                }
        }
-       RETURN(0);
+unlock:
+       mutex_unlock(&lo->ldo_layout_mutex);
+       RETURN(rc);
 }
 
 static bool lod_obj_attr_set_comp_skip_cb(const struct lu_env *env,
@@ -1144,9 +1262,11 @@ static bool lod_obj_attr_set_comp_skip_cb(const struct lu_env *env,
                }
                break;
        }
+       case LCM_FL_RDONLY:
+       case LCM_FL_SYNC_PENDING:
+               break;
        default:
                LASSERTF(0, "impossible: %d\n", lo->ldo_flr_state);
-       case LCM_FL_SYNC_PENDING:
                break;
        }
 
@@ -1241,6 +1361,8 @@ static int lod_declare_attr_set(const struct lu_env *env,
                for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
                        if (lo->ldo_stripe[i] == NULL)
                                continue;
+                       if (!dt_object_exists(lo->ldo_stripe[i]))
+                               continue;
                        rc = lod_sub_declare_attr_set(env, lo->ldo_stripe[i],
                                                      attr, th);
                        if (rc != 0)
@@ -1385,7 +1507,7 @@ static int lod_attr_set(const struct lu_env *env,
                buf->lb_len = info->lti_ea_store_size;
                lmm = info->lti_ea_store;
                magic = le32_to_cpu(lmm->lmm_magic);
-               if (magic == LOV_MAGIC_COMP_V1) {
+               if (magic == LOV_MAGIC_COMP_V1 || magic == LOV_MAGIC_SEL) {
                        struct lov_comp_md_v1 *lcm = buf->lb_buf;
                        struct lov_comp_md_entry_v1 *lcme =
                                                &lcm->lcm_entries[0];
@@ -1419,7 +1541,8 @@ static int lod_attr_set(const struct lu_env *env,
                buf->lb_buf = info->lti_ea_store;
                buf->lb_len = info->lti_ea_store_size;
                lcm = buf->lb_buf;
-               if (le32_to_cpu(lcm->lcm_magic) != LOV_MAGIC_COMP_V1)
+               if (le32_to_cpu(lcm->lcm_magic) != LOV_MAGIC_COMP_V1 &&
+                   le32_to_cpu(lcm->lcm_magic) != LOV_MAGIC_SEL)
                        RETURN(-EINVAL);
 
                le32_add_cpu(&lcm->lcm_layout_gen, 1);
@@ -1454,21 +1577,35 @@ static int lod_xattr_get(const struct lu_env *env, struct dt_object *dt,
        rc = dt_xattr_get(env, dt_object_child(dt), buf, name);
        if (strcmp(name, XATTR_NAME_LMV) == 0) {
                struct lmv_mds_md_v1    *lmv1;
+               struct lmv_foreign_md   *lfm;
                int                      rc1 = 0;
 
                if (rc > (typeof(rc))sizeof(*lmv1))
                        RETURN(rc);
 
-               if (rc < (typeof(rc))sizeof(*lmv1))
+               /* short (<= sizeof(struct lmv_mds_md_v1)) foreign LMV case */
+               /* XXX empty foreign LMV is not allowed */
+               if (rc <= offsetof(typeof(*lfm), lfm_value))
                        RETURN(rc = rc > 0 ? -EINVAL : rc);
 
                if (buf->lb_buf == NULL || buf->lb_len == 0) {
-                       CLASSERT(sizeof(*lmv1) <= sizeof(info->lti_key));
+                       BUILD_BUG_ON(sizeof(*lmv1) > sizeof(info->lti_key));
 
+                       /* lti_buf is large enough for *lmv1 or a short
+                        * (<= sizeof(struct lmv_mds_md_v1)) foreign LMV
+                        */
                        info->lti_buf.lb_buf = info->lti_key;
                        info->lti_buf.lb_len = sizeof(*lmv1);
                        rc = dt_xattr_get(env, dt_object_child(dt),
                                          &info->lti_buf, name);
+                       if (unlikely(rc <= offsetof(typeof(*lfm),
+                                                   lfm_value)))
+                               RETURN(rc = rc > 0 ? -EINVAL : rc);
+
+                       lfm = info->lti_buf.lb_buf;
+                       if (le32_to_cpu(lfm->lfm_magic) == LMV_MAGIC_FOREIGN)
+                               RETURN(rc);
+
                        if (unlikely(rc != sizeof(*lmv1)))
                                RETURN(rc = rc > 0 ? -EINVAL : rc);
 
@@ -1479,8 +1616,15 @@ static int lod_xattr_get(const struct lu_env *env, struct dt_object *dt,
                        if (le32_to_cpu(lmv1->lmv_magic) == LMV_MAGIC_V1)
                                rc = lmv_mds_md_size(
                                        le32_to_cpu(lmv1->lmv_stripe_count),
-                                       LMV_MAGIC_V1);
+                                       le32_to_cpu(lmv1->lmv_magic));
                } else {
+                       lmv1 = buf->lb_buf;
+                       if (le32_to_cpu(lmv1->lmv_magic) != LMV_MAGIC_V1)
+                               RETURN(rc);
+
+                       if (rc != sizeof(*lmv1))
+                               RETURN(rc = rc > 0 ? -EINVAL : rc);
+
                        rc1 = lod_load_lmv_shards(env, lod_dt_obj(dt),
                                                  buf, false);
                }
@@ -1488,6 +1632,13 @@ static int lod_xattr_get(const struct lu_env *env, struct dt_object *dt,
                RETURN(rc = rc1 != 0 ? rc1 : rc);
        }
 
+       if ((rc > 0) && buf->lb_buf && strcmp(name, XATTR_NAME_LOV) == 0) {
+               struct lov_comp_md_v1 *lcm = buf->lb_buf;
+
+               if (lcm->lcm_magic == cpu_to_le32(LOV_MAGIC_SEL))
+                       lcm->lcm_magic = cpu_to_le32(LOV_MAGIC_COMP_V1);
+       }
+
        if (rc != -ENODATA || !S_ISDIR(dt->do_lu.lo_header->loh_attr & S_IFMT))
                RETURN(rc);
 
@@ -1504,7 +1655,7 @@ static int lod_xattr_get(const struct lu_env *env, struct dt_object *dt,
 
        if (is_root && strcmp(XATTR_NAME_LOV, name) == 0) {
                struct lov_user_md *lum = buf->lb_buf;
-               struct lov_desc    *desc = &dev->lod_desc;
+               struct lov_desc *desc = &dev->lod_ost_descs.ltd_lov_desc;
 
                if (buf->lb_buf == NULL) {
                        rc = sizeof(*lum);
@@ -1614,7 +1765,8 @@ static int lod_prep_lmv_md(const struct lu_env *env, struct dt_object *dt,
        lmm1->lmv_magic = cpu_to_le32(LMV_MAGIC);
        lmm1->lmv_stripe_count = cpu_to_le32(stripe_count);
        lmm1->lmv_hash_type = cpu_to_le32(lo->ldo_dir_hash_type);
-       if (lo->ldo_dir_hash_type & LMV_HASH_FLAG_MIGRATION) {
+       lmm1->lmv_layout_version = cpu_to_le32(lo->ldo_dir_layout_version);
+       if (lod_is_layout_changing(lo)) {
                lmm1->lmv_migrate_hash = cpu_to_le32(lo->ldo_dir_migrate_hash);
                lmm1->lmv_migrate_offset =
                        cpu_to_le32(lo->ldo_dir_migrate_offset);
@@ -1662,7 +1814,8 @@ int lod_parse_dir_striping(const struct lu_env *env, struct lod_object *lo,
 
        LASSERT(mutex_is_locked(&lo->ldo_layout_mutex));
 
-       if (le32_to_cpu(lmv1->lmv_hash_type) & LMV_HASH_FLAG_MIGRATION)
+       /* XXX may be useless as not called for foreign LMV ?? */
+       if (le32_to_cpu(lmv1->lmv_magic) == LMV_MAGIC_FOREIGN)
                RETURN(0);
 
        if (le32_to_cpu(lmv1->lmv_magic) == LMV_MAGIC_STRIPE) {
@@ -1670,15 +1823,11 @@ int lod_parse_dir_striping(const struct lu_env *env, struct lod_object *lo,
                RETURN(0);
        }
 
-       if (le32_to_cpu(lmv1->lmv_magic) != LMV_MAGIC_V1)
+       if (!lmv_is_sane(lmv1))
                RETURN(-EINVAL);
 
-       if (le32_to_cpu(lmv1->lmv_stripe_count) < 1)
-               RETURN(0);
-
        LASSERT(lo->ldo_stripe == NULL);
-       OBD_ALLOC(stripe, sizeof(stripe[0]) *
-                 (le32_to_cpu(lmv1->lmv_stripe_count)));
+       OBD_ALLOC_PTR_ARRAY(stripe, le32_to_cpu(lmv1->lmv_stripe_count));
        if (stripe == NULL)
                RETURN(-ENOMEM);
 
@@ -1689,8 +1838,10 @@ int lod_parse_dir_striping(const struct lu_env *env, struct lod_object *lo,
                __u32                   idx;
 
                fid_le_to_cpu(fid, &lmv1->lmv_stripe_fids[i]);
-               if (!fid_is_sane(fid))
-                       GOTO(out, rc = -ESTALE);
+               if (!fid_is_sane(fid)) {
+                       stripe[i] = NULL;
+                       continue;
+               }
 
                rc = lod_fld_lookup(env, lod, fid, &idx, &type);
                if (rc != 0)
@@ -1717,8 +1868,13 @@ int lod_parse_dir_striping(const struct lu_env *env, struct lod_object *lo,
        }
 out:
        lo->ldo_stripe = stripe;
+       lo->ldo_is_foreign = 0;
        lo->ldo_dir_stripe_count = le32_to_cpu(lmv1->lmv_stripe_count);
        lo->ldo_dir_stripes_allocated = le32_to_cpu(lmv1->lmv_stripe_count);
+       lo->ldo_dir_layout_version = le32_to_cpu(lmv1->lmv_layout_version);
+       lo->ldo_dir_migrate_offset = le32_to_cpu(lmv1->lmv_migrate_offset);
+       lo->ldo_dir_migrate_hash = le32_to_cpu(lmv1->lmv_migrate_hash);
+       lo->ldo_dir_hash_type = le32_to_cpu(lmv1->lmv_hash_type);
        if (rc != 0)
                lod_striping_free_nolock(env, lo);
 
@@ -1785,31 +1941,78 @@ static int lod_dir_declare_create_stripes(const struct lu_env *env,
                struct linkea_data       ldata          = { NULL };
                struct lu_buf           linkea_buf;
 
-               rc = lod_sub_declare_create(env, dto, attr, NULL, dof, th);
-               if (rc != 0)
-                       GOTO(out, rc);
+               /* OBD_FAIL_MDS_STRIPE_FID may leave stripe uninitialized */
+               if (!dto)
+                       continue;
 
-               if (!dt_try_as_dir(env, dto))
-                       GOTO(out, rc = -EINVAL);
+               /* directory split skip create for existing stripes */
+               if (!(lod_is_splitting(lo) && i < lo->ldo_dir_split_offset)) {
+                       rc = lod_sub_declare_create(env, dto, attr, NULL, dof,
+                                                   th);
+                       if (rc != 0)
+                               GOTO(out, rc);
 
-               rc = lod_sub_declare_ref_add(env, dto, th);
-               if (rc != 0)
-                       GOTO(out, rc);
+                       if (!dt_try_as_dir(env, dto))
+                               GOTO(out, rc = -EINVAL);
 
-               rec->rec_fid = lu_object_fid(&dto->do_lu);
-               rc = lod_sub_declare_insert(env, dto,
-                                           (const struct dt_rec *)rec,
-                                           (const struct dt_key *)dot, th);
-               if (rc != 0)
-                       GOTO(out, rc);
+                       rc = lod_sub_declare_ref_add(env, dto, th);
+                       if (rc != 0)
+                               GOTO(out, rc);
 
-               /* master stripe FID will be put to .. */
-               rec->rec_fid = lu_object_fid(&dt->do_lu);
-               rc = lod_sub_declare_insert(env, dto,
-                                           (const struct dt_rec *)rec,
-                                           (const struct dt_key *)dotdot, th);
-               if (rc != 0)
-                       GOTO(out, rc);
+                       rec->rec_fid = lu_object_fid(&dto->do_lu);
+                       rc = lod_sub_declare_insert(env, dto,
+                                                   (const struct dt_rec *)rec,
+                                                   (const struct dt_key *)dot,
+                                                   th);
+                       if (rc != 0)
+                               GOTO(out, rc);
+
+                       /* master stripe FID will be put to .. */
+                       rec->rec_fid = lu_object_fid(&dt->do_lu);
+                       rc = lod_sub_declare_insert(env, dto,
+                                                 (const struct dt_rec *)rec,
+                                                 (const struct dt_key *)dotdot,
+                                                 th);
+                       if (rc != 0)
+                               GOTO(out, rc);
+
+                       if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_SLAVE_NAME) &&
+                           cfs_fail_val == i)
+                               snprintf(stripe_name, sizeof(info->lti_key),
+                                        DFID":%u",
+                                        PFID(lu_object_fid(&dto->do_lu)),
+                                        i + 1);
+                       else
+                               snprintf(stripe_name, sizeof(info->lti_key),
+                                        DFID":%u",
+                                        PFID(lu_object_fid(&dto->do_lu)), i);
+
+                       sname = lod_name_get(env, stripe_name,
+                                            strlen(stripe_name));
+                       rc = linkea_links_new(&ldata, &info->lti_linkea_buf,
+                                             sname, lu_object_fid(&dt->do_lu));
+                       if (rc != 0)
+                               GOTO(out, rc);
+
+                       linkea_buf.lb_buf = ldata.ld_buf->lb_buf;
+                       linkea_buf.lb_len = ldata.ld_leh->leh_len;
+                       rc = lod_sub_declare_xattr_set(env, dto, &linkea_buf,
+                                                      XATTR_NAME_LINK, 0, th);
+                       if (rc != 0)
+                               GOTO(out, rc);
+
+                       rec->rec_fid = lu_object_fid(&dto->do_lu);
+                       rc = lod_sub_declare_insert(env, dt_object_child(dt),
+                                       (const struct dt_rec *)rec,
+                                       (const struct dt_key *)stripe_name, th);
+                       if (rc != 0)
+                               GOTO(out, rc);
+
+                       rc = lod_sub_declare_ref_add(env, dt_object_child(dt),
+                                                    th);
+                       if (rc != 0)
+                               GOTO(out, rc);
+               }
 
                if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_SLAVE_LMV) ||
                    cfs_fail_val != i) {
@@ -1825,39 +2028,6 @@ static int lod_dir_declare_create_stripes(const struct lu_env *env,
                        if (rc != 0)
                                GOTO(out, rc);
                }
-
-               if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_SLAVE_NAME) &&
-                   cfs_fail_val == i)
-                       snprintf(stripe_name, sizeof(info->lti_key), DFID":%u",
-                               PFID(lu_object_fid(&dto->do_lu)), i + 1);
-               else
-                       snprintf(stripe_name, sizeof(info->lti_key), DFID":%u",
-                               PFID(lu_object_fid(&dto->do_lu)), i);
-
-               sname = lod_name_get(env, stripe_name, strlen(stripe_name));
-               rc = linkea_links_new(&ldata, &info->lti_linkea_buf,
-                                     sname, lu_object_fid(&dt->do_lu));
-               if (rc != 0)
-                       GOTO(out, rc);
-
-               linkea_buf.lb_buf = ldata.ld_buf->lb_buf;
-               linkea_buf.lb_len = ldata.ld_leh->leh_len;
-               rc = lod_sub_declare_xattr_set(env, dto, &linkea_buf,
-                                              XATTR_NAME_LINK, 0, th);
-               if (rc != 0)
-                       GOTO(out, rc);
-
-               rec->rec_fid = lu_object_fid(&dto->do_lu);
-               rc = lod_sub_declare_insert(env, dt_object_child(dt),
-                                           (const struct dt_rec *)rec,
-                                           (const struct dt_key *)stripe_name,
-                                           th);
-               if (rc != 0)
-                       GOTO(out, rc);
-
-               rc = lod_sub_declare_ref_add(env, dt_object_child(dt), th);
-               if (rc != 0)
-                       GOTO(out, rc);
        }
 
        rc = lod_sub_declare_xattr_set(env, dt_object_child(dt),
@@ -1871,75 +2041,72 @@ out:
        RETURN(rc);
 }
 
-static int lod_prep_md_striped_create(const struct lu_env *env,
-                                     struct dt_object *dt,
-                                     struct lu_attr *attr,
-                                     const struct lmv_user_md_v1 *lum,
-                                     struct dt_object_format *dof,
-                                     struct thandle *th)
+/**
+ * Allocate a striping on a predefined set of MDTs.
+ *
+ * Allocates new striping using the MDT index range provided by the data from
+ * the lum_obejcts contained in the lmv_user_md passed to this method if
+ * \a is_specific is true; or allocates new layout starting from MDT index in
+ * lo->ldo_dir_stripe_offset. The exact order of MDTs is not important and
+ * varies depending on MDT status. The number of stripes needed and stripe
+ * offset are taken from the object. If that number cannot be met, then the
+ * function returns an error and then it's the caller's responsibility to
+ * release the stripes allocated. All the internal structures are protected,
+ * but no concurrent allocation is allowed on the same objects.
+ *
+ * \param[in] env              execution environment for this thread
+ * \param[in] lo               LOD object
+ * \param[out] stripes         striping created
+ * \param[out] mdt_indices     MDT indices of striping created
+ * \param[in] is_specific      true if the MDTs are provided by lum; false if
+ *                             only the starting MDT index is provided
+ *
+ * \retval positive    stripes allocated, including the first stripe allocated
+ *                     outside
+ * \retval negative    errno on failure
+ */
+static int lod_mdt_alloc_specific(const struct lu_env *env,
+                                 struct lod_object *lo,
+                                 struct dt_object **stripes,
+                                 __u32 *mdt_indices, bool is_specific)
 {
-       struct lod_thread_info  *info = lod_env_info(env);
-       struct lod_device       *lod = lu2lod_dev(dt->do_lu.lo_dev);
-       struct lod_tgt_descs    *ltd = &lod->lod_mdt_descs;
-       struct lod_object       *lo = lod_dt_obj(dt);
-       struct dt_object        **stripe;
-       __u32                   stripe_count;
-       int                     *idx_array;
-       __u32                   master_index;
-       int                     rc = 0;
-       __u32                   i;
-       __u32                   j;
-       bool                    is_specific = false;
-       ENTRY;
-
-       /* The lum has been verifed in lod_verify_md_striping */
-       LASSERT(le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC ||
-               le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC_SPECIFIC);
-       LASSERT(le32_to_cpu(lum->lum_stripe_count) > 0);
-
-       stripe_count = le32_to_cpu(lum->lum_stripe_count);
-
-       OBD_ALLOC(idx_array, sizeof(idx_array[0]) * stripe_count);
-       if (idx_array == NULL)
-               RETURN(-ENOMEM);
-
-       OBD_ALLOC(stripe, sizeof(stripe[0]) * stripe_count);
-       if (stripe == NULL)
-               GOTO(out_free, rc = -ENOMEM);
+       struct lod_device *lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+       struct lu_tgt_descs *ltd = &lod->lod_mdt_descs;
+       struct lu_tgt_desc *tgt = NULL;
+       struct lu_object_conf conf = { .loc_flags = LOC_F_NEW };
+       struct dt_device *tgt_dt = NULL;
+       struct lu_fid fid = { 0 };
+       struct dt_object *dto;
+       u32 master_index;
+       u32 stripe_count = lo->ldo_dir_stripe_count;
+       int stripe_idx = 1;
+       int j;
+       int idx;
+       int rc;
 
-       /* Start index must be the master MDT */
        master_index = lu_site2seq(lod2lu_dev(lod)->ld_site)->ss_node_id;
-       idx_array[0] = master_index;
-       if (le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC_SPECIFIC) {
-               is_specific = true;
-               for (i = 1; i < stripe_count; i++)
-                       idx_array[i] = le32_to_cpu(lum->lum_objects[i].lum_mds);
-       }
-
-       for (i = 0; i < stripe_count; i++) {
-               struct lod_tgt_desc     *tgt = NULL;
-               struct dt_object        *dto;
-               struct lu_fid           fid = { 0 };
-               int                     idx;
-               struct lu_object_conf   conf = { 0 };
-               struct dt_device        *tgt_dt = NULL;
+       if (!is_specific && stripe_count > 1)
+               /* Set the start index for the 2nd stripe allocation */
+               mdt_indices[1] = (mdt_indices[0] + 1) %
+                                       (lod->lod_remote_mdt_count + 1);
 
+       for (; stripe_idx < stripe_count; stripe_idx++) {
                /* Try to find next avaible target */
-               idx = idx_array[i];
+               idx = mdt_indices[stripe_idx];
                for (j = 0; j < lod->lod_remote_mdt_count;
                     j++, idx = (idx + 1) % (lod->lod_remote_mdt_count + 1)) {
                        bool already_allocated = false;
                        __u32 k;
 
                        CDEBUG(D_INFO, "try idx %d, mdt cnt %u, allocated %u\n",
-                              idx, lod->lod_remote_mdt_count + 1, i);
+                              idx, lod->lod_remote_mdt_count + 1, stripe_idx);
 
                        if (likely(!is_specific &&
                                   !OBD_FAIL_CHECK(OBD_FAIL_LARGE_STRIPE))) {
                                /* check whether the idx already exists
                                 * in current allocated array */
-                               for (k = 0; k < i; k++) {
-                                       if (idx_array[k] == idx) {
+                               for (k = 0; k < stripe_idx; k++) {
+                                       if (mdt_indices[k] == idx) {
                                                already_allocated = true;
                                                break;
                                        }
@@ -1951,38 +2118,33 @@ static int lod_prep_md_striped_create(const struct lu_env *env,
 
                        /* Sigh, this index is not in the bitmap, let's check
                         * next available target */
-                       if (!cfs_bitmap_check(ltd->ltd_tgt_bitmap, idx) &&
+                       if (!test_bit(idx, ltd->ltd_tgt_bitmap) &&
                            idx != master_index)
                                continue;
 
                        if (idx == master_index) {
                                /* Allocate the FID locally */
-                               rc = obd_fid_alloc(env, lod->lod_child_exp,
-                                                  &fid, NULL);
-                               if (rc < 0)
-                                       GOTO(out_put, rc);
                                tgt_dt = lod->lod_child;
+                               rc = dt_fid_alloc(env, tgt_dt, &fid, NULL,
+                                                 NULL);
+                               if (rc < 0)
+                                       continue;
                                break;
                        }
 
                        /* check the status of the OSP */
                        tgt = LTD_TGT(ltd, idx);
-                       if (tgt == NULL)
+                       if (!tgt)
                                continue;
 
                        tgt_dt = tgt->ltd_tgt;
-                       rc = dt_statfs(env, tgt_dt, &info->lti_osfs);
-                       if (rc) {
+                       if (!tgt->ltd_active)
                                /* this OSP doesn't feel well */
-                               rc = 0;
                                continue;
-                       }
 
-                       rc = obd_fid_alloc(env, tgt->ltd_exp, &fid, NULL);
-                       if (rc < 0) {
-                               rc = 0;
+                       rc = dt_fid_alloc(env, tgt_dt, &fid, NULL, NULL);
+                       if (rc < 0)
                                continue;
-                       }
 
                        break;
                }
@@ -1990,15 +2152,16 @@ static int lod_prep_md_striped_create(const struct lu_env *env,
                /* Can not allocate more stripes */
                if (j == lod->lod_remote_mdt_count) {
                        CDEBUG(D_INFO, "%s: require stripes %u only get %d\n",
-                              lod2obd(lod)->obd_name, stripe_count, i);
+                              lod2obd(lod)->obd_name, stripe_count,
+                              stripe_idx);
                        break;
                }
 
                CDEBUG(D_INFO, "Get idx %d, for stripe %d "DFID"\n",
-                      idx, i, PFID(&fid));
-               idx_array[i] = idx;
+                      idx, stripe_idx, PFID(&fid));
+               mdt_indices[stripe_idx] = idx;
                /* Set the start index for next stripe allocation */
-               if (!is_specific && i < stripe_count - 1) {
+               if (!is_specific && stripe_idx < stripe_count - 1) {
                        /*
                         * for large dir test, put all other slaves on one
                         * remote MDT, otherwise we may save too many local
@@ -2006,51 +2169,205 @@ static int lod_prep_md_striped_create(const struct lu_env *env,
                         */
                        if (unlikely(OBD_FAIL_CHECK(OBD_FAIL_LARGE_STRIPE)))
                                idx = master_index;
-                       idx_array[i + 1] = (idx + 1) %
+                       mdt_indices[stripe_idx + 1] = (idx + 1) %
                                           (lod->lod_remote_mdt_count + 1);
                }
                /* tgt_dt and fid must be ready after search avaible OSP
                 * in the above loop */
                LASSERT(tgt_dt != NULL);
                LASSERT(fid_is_sane(&fid));
-               conf.loc_flags = LOC_F_NEW;
-               dto = dt_locate_at(env, tgt_dt, &fid,
-                                  dt->do_lu.lo_dev->ld_site->ls_top_dev,
-                                  &conf);
-               if (IS_ERR(dto))
-                       GOTO(out_put, rc = PTR_ERR(dto));
-               stripe[i] = dto;
-       }
 
-       lo->ldo_dir_striped = 1;
-       lo->ldo_stripe = stripe;
-       lo->ldo_dir_stripe_count = i;
-       lo->ldo_dir_stripes_allocated = stripe_count;
-       smp_mb();
-       lo->ldo_dir_stripe_loaded = 1;
+               /* fail a remote stripe FID allocation */
+               if (stripe_idx && OBD_FAIL_CHECK(OBD_FAIL_MDS_STRIPE_FID))
+                       continue;
 
-       if (lo->ldo_dir_stripe_count == 0)
-               GOTO(out_put, rc = -ENOSPC);
+               dto = dt_locate_at(env, tgt_dt, &fid,
+                                 lo->ldo_obj.do_lu.lo_dev->ld_site->ls_top_dev,
+                                 &conf);
+               if (IS_ERR(dto)) {
+                       rc = PTR_ERR(dto);
+                       goto error;
+               }
 
-       rc = lod_dir_declare_create_stripes(env, dt, attr, dof, th);
-       if (rc != 0)
-               GOTO(out_put, rc);
+               stripes[stripe_idx] = dto;
+       }
 
-out_put:
-       if (rc < 0) {
-               for (i = 0; i < stripe_count; i++)
-                       if (stripe[i] != NULL)
-                               dt_object_put(env, stripe[i]);
-               OBD_FREE(stripe, sizeof(stripe[0]) * stripe_count);
-               lo->ldo_dir_stripe_count = 0;
-               lo->ldo_dir_stripes_allocated = 0;
-               lo->ldo_stripe = NULL;
+       return stripe_idx;
+
+error:
+       for (j = 1; j < stripe_idx; j++) {
+               LASSERT(stripes[j] != NULL);
+               dt_object_put(env, stripes[j]);
+               stripes[j] = NULL;
+       }
+       return rc;
+}
+
+static int lod_prep_md_striped_create(const struct lu_env *env,
+                                     struct dt_object *dt,
+                                     struct lu_attr *attr,
+                                     const struct lmv_user_md_v1 *lum,
+                                     struct dt_object_format *dof,
+                                     struct thandle *th)
+{
+       struct lod_device *lod = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object **stripes;
+       struct lu_object_conf conf = { .loc_flags = LOC_F_NEW };
+       struct lu_fid fid = { 0 };
+       __u32 stripe_count;
+       int i;
+       int rc = 0;
+
+       ENTRY;
+
+       /* The lum has been verifed in lod_verify_md_striping */
+       LASSERT(le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC ||
+               le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC_SPECIFIC);
+
+       stripe_count = lo->ldo_dir_stripe_count;
+
+       OBD_ALLOC_PTR_ARRAY(stripes, stripe_count);
+       if (!stripes)
+               RETURN(-ENOMEM);
+
+       /* Allocate the first stripe locally */
+       rc = dt_fid_alloc(env, lod->lod_child, &fid, NULL, NULL);
+       if (rc < 0)
+               GOTO(out, rc);
+
+       stripes[0] = dt_locate_at(env, lod->lod_child, &fid,
+                                 dt->do_lu.lo_dev->ld_site->ls_top_dev, &conf);
+       if (IS_ERR(stripes[0]))
+               GOTO(out, rc = PTR_ERR(stripes[0]));
+
+       if (lo->ldo_dir_stripe_offset == LMV_OFFSET_DEFAULT) {
+               lod_qos_statfs_update(env, lod, &lod->lod_mdt_descs);
+               rc = lod_mdt_alloc_qos(env, lo, stripes, 1, stripe_count);
+               if (rc == -EAGAIN)
+                       rc = lod_mdt_alloc_rr(env, lo, stripes, 1,
+                                             stripe_count);
+       } else {
+               int *idx_array;
+               bool is_specific = false;
+
+               OBD_ALLOC_PTR_ARRAY(idx_array, stripe_count);
+               if (!idx_array)
+                       GOTO(out, rc = -ENOMEM);
+
+               if (le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC_SPECIFIC) {
+                       is_specific = true;
+                       for (i = 0; i < stripe_count; i++)
+                               idx_array[i] =
+                                      le32_to_cpu(lum->lum_objects[i].lum_mds);
+               }
+
+               /* stripe 0 is local */
+               idx_array[0] =
+                       lu_site2seq(lod2lu_dev(lod)->ld_site)->ss_node_id;
+               rc = lod_mdt_alloc_specific(env, lo, stripes, idx_array,
+                                           is_specific);
+               OBD_FREE_PTR_ARRAY(idx_array, stripe_count);
        }
 
-out_free:
-       OBD_FREE(idx_array, sizeof(idx_array[0]) * stripe_count);
+       if (rc < 0)
+               GOTO(out, rc);
+
+       LASSERT(rc > 0);
+
+       lo->ldo_dir_striped = 1;
+       lo->ldo_stripe = stripes;
+       lo->ldo_dir_stripe_count = rc;
+       lo->ldo_dir_stripes_allocated = stripe_count;
+       smp_mb();
+       lo->ldo_dir_stripe_loaded = 1;
+
+       rc = lod_dir_declare_create_stripes(env, dt, attr, dof, th);
+       if (rc < 0)
+               lod_striping_free(env, lo);
 
        RETURN(rc);
+
+out:
+       LASSERT(rc < 0);
+       if (!IS_ERR_OR_NULL(stripes[0]))
+               dt_object_put(env, stripes[0]);
+       for (i = 1; i < stripe_count; i++)
+               LASSERT(!stripes[i]);
+       OBD_FREE_PTR_ARRAY(stripes, stripe_count);
+
+       return rc;
+}
+
+/**
+ *
+ * Alloc cached foreign LOV
+ *
+ * \param[in] lo        object
+ * \param[in] size      size of foreign LOV
+ *
+ * \retval             0 on success
+ * \retval             negative if failed
+ */
+int lod_alloc_foreign_lov(struct lod_object *lo, size_t size)
+{
+       OBD_ALLOC_LARGE(lo->ldo_foreign_lov, size);
+       if (lo->ldo_foreign_lov == NULL)
+               return -ENOMEM;
+       lo->ldo_foreign_lov_size = size;
+       lo->ldo_is_foreign = 1;
+       return 0;
+}
+
+/**
+ *
+ * Free cached foreign LOV
+ *
+ * \param[in] lo        object
+ */
+void lod_free_foreign_lov(struct lod_object *lo)
+{
+       if (lo->ldo_foreign_lov != NULL)
+               OBD_FREE_LARGE(lo->ldo_foreign_lov, lo->ldo_foreign_lov_size);
+       lo->ldo_foreign_lov = NULL;
+       lo->ldo_foreign_lov_size = 0;
+       lo->ldo_is_foreign = 0;
+}
+
+/**
+ *
+ * Alloc cached foreign LMV
+ *
+ * \param[in] lo        object
+ * \param[in] size      size of foreign LMV
+ *
+ * \retval              0 on success
+ * \retval              negative if failed
+ */
+int lod_alloc_foreign_lmv(struct lod_object *lo, size_t size)
+{
+       OBD_ALLOC_LARGE(lo->ldo_foreign_lmv, size);
+       if (lo->ldo_foreign_lmv == NULL)
+               return -ENOMEM;
+       lo->ldo_foreign_lmv_size = size;
+       lo->ldo_is_foreign = 1;
+
+       return 0;
+}
+
+/**
+ *
+ * Free cached foreign LMV
+ *
+ * \param[in] lo        object
+ */
+void lod_free_foreign_lmv(struct lod_object *lo)
+{
+       if (lo->ldo_foreign_lmv != NULL)
+               OBD_FREE_LARGE(lo->ldo_foreign_lmv, lo->ldo_foreign_lmv_size);
+       lo->ldo_foreign_lmv = NULL;
+       lo->ldo_foreign_lmv_size = 0;
+       lo->ldo_is_foreign = 0;
 }
 
 /**
@@ -2079,19 +2396,30 @@ static int lod_declare_xattr_set_lmv(const struct lu_env *env,
                                     struct dt_object_format *dof,
                                     struct thandle *th)
 {
-       struct lod_object       *lo = lod_dt_obj(dt);
-       struct lmv_user_md_v1   *lum = lum_buf->lb_buf;
-       int                     rc;
-       ENTRY;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lmv_user_md_v1 *lum = lum_buf->lb_buf;
+       int rc;
 
+       ENTRY;
        LASSERT(lum != NULL);
 
-       CDEBUG(D_INFO, "lum magic = %x count = %u offset = %d\n",
-              le32_to_cpu(lum->lum_magic), le32_to_cpu(lum->lum_stripe_count),
-              (int)le32_to_cpu(lum->lum_stripe_offset));
+       CDEBUG(D_INFO,
+              "lum magic=%x hash=%x count=%u offset=%d inherit=%u rr=%u\n",
+              le32_to_cpu(lum->lum_magic), le32_to_cpu(lum->lum_hash_type),
+              le32_to_cpu(lum->lum_stripe_count),
+              (int)le32_to_cpu(lum->lum_stripe_offset),
+              lum->lum_max_inherit, lum->lum_max_inherit_rr);
 
-       if (lo->ldo_dir_stripe_count == 0)
+       if (lo->ldo_dir_stripe_count == 0) {
+               if (lo->ldo_is_foreign) {
+                       rc = lod_alloc_foreign_lmv(lo, lum_buf->lb_len);
+                       if (rc != 0)
+                               GOTO(out, rc);
+                       memcpy(lo->ldo_foreign_lmv, lum, lum_buf->lb_len);
+                       lo->ldo_dir_stripe_loaded = 1;
+               }
                GOTO(out, rc = 0);
+       }
 
        /* prepare dir striped objects */
        rc = lod_prep_md_striped_create(env, dt, attr, lum, dof, th);
@@ -2106,341 +2434,148 @@ out:
 }
 
 /**
- * Append source stripes after target stripes for migrating directory. NB, we
- * only need to declare this, the append is done inside lod_xattr_set_lmv().
+ * Set or replace striped directory layout, and LFSCK may set layout on a plain
+ * directory, so don't check stripe count.
  *
  * \param[in] env      execution environment
  * \param[in] dt       target object
- * \param[in] buf      LMV buf which contains source stripe fids
+ * \param[in] lmv_buf  LMV buf which contains source stripe FIDs
+ * \param[in] fl       set or replace
  * \param[in] th       transaction handle
  *
  * \retval             0 on success
  * \retval             negative if failed
  */
-static int lod_dir_declare_layout_add(const struct lu_env *env,
-                                     struct dt_object *dt,
-                                     const struct lu_buf *buf,
-                                     struct thandle *th)
+static int lod_dir_layout_set(const struct lu_env *env,
+                             struct dt_object *dt,
+                             const struct lu_buf *lmv_buf,
+                             int fl,
+                             struct thandle *th)
 {
-       struct lod_thread_info *info = lod_env_info(env);
-       struct lod_device *lod = lu2lod_dev(dt->do_lu.lo_dev);
-       struct lod_tgt_descs *ltd = &lod->lod_mdt_descs;
-       struct lod_object *lo = lod_dt_obj(dt);
        struct dt_object *next = dt_object_child(dt);
-       struct dt_object_format *dof = &info->lti_format;
-       struct lmv_mds_md_v1 *lmv = buf->lb_buf;
-       struct dt_object **stripe;
-       __u32 stripe_count = le32_to_cpu(lmv->lmv_stripe_count);
-       struct lu_fid *fid = &info->lti_fid;
-       struct lod_tgt_desc *tgt;
-       struct dt_object *dto;
-       struct dt_device *tgt_dt;
-       int type = LU_SEQ_RANGE_ANY;
-       struct dt_insert_rec *rec = &info->lti_dt_rec;
-       char *stripe_name = info->lti_key;
-       struct lu_name *sname;
-       struct linkea_data ldata = { NULL };
-       struct lu_buf linkea_buf;
-       __u32 idx;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lod_device *lod = lu2lod_dev(lod2lu_obj(lo)->lo_dev);
+       struct lmv_mds_md_v1 *lmv = lmv_buf->lb_buf;
+       struct lmv_mds_md_v1 *slave_lmv;
+       struct lu_buf slave_buf;
        int i;
        int rc;
 
        ENTRY;
 
-       if (le32_to_cpu(lmv->lmv_magic) != LMV_MAGIC_V1)
+       if (!lmv_is_sane2(lmv))
                RETURN(-EINVAL);
 
-       if (stripe_count == 0)
-               RETURN(-EINVAL);
+       /* adjust hash for dir merge, which may not be set in user command */
+       if (lmv_is_merging(lmv) &&
+           !(lmv->lmv_migrate_hash & LMV_HASH_TYPE_MASK))
+               lmv->lmv_merge_hash |=
+                       lod->lod_mdt_descs.ltd_lmv_desc.ld_pattern &
+                       LMV_HASH_TYPE_MASK;
 
-       dof->dof_type = DFT_DIR;
+       LMV_DEBUG(D_INFO, lmv, "set");
 
-       OBD_ALLOC(stripe,
-                 sizeof(*stripe) * (lo->ldo_dir_stripe_count + stripe_count));
-       if (stripe == NULL)
+       rc = lod_sub_xattr_set(env, next, lmv_buf, XATTR_NAME_LMV, fl, th);
+       if (rc)
+               RETURN(rc);
+
+       /* directory restripe may update stripe LMV directly */
+       if (!lo->ldo_dir_stripe_count)
+               RETURN(0);
+
+       lo->ldo_dir_hash_type = le32_to_cpu(lmv->lmv_hash_type);
+       lo->ldo_dir_migrate_offset = le32_to_cpu(lmv->lmv_migrate_offset);
+       lo->ldo_dir_migrate_hash = le32_to_cpu(lmv->lmv_migrate_hash);
+       lo->ldo_dir_layout_version = le32_to_cpu(lmv->lmv_layout_version);
+
+       OBD_ALLOC_PTR(slave_lmv);
+       if (!slave_lmv)
                RETURN(-ENOMEM);
 
-       for (i = 0; i < lo->ldo_dir_stripe_count; i++)
-               stripe[i] = lo->ldo_stripe[i];
+       lod_prep_slave_lmv_md(slave_lmv, lmv);
+       slave_buf.lb_buf = slave_lmv;
+       slave_buf.lb_len = sizeof(*slave_lmv);
 
-       for (i = 0; i < stripe_count; i++) {
-               fid_le_to_cpu(fid,
-                       &lmv->lmv_stripe_fids[i]);
-               if (!fid_is_sane(fid))
-                       GOTO(out, rc = -ESTALE);
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               if (!lo->ldo_stripe[i])
+                       continue;
 
-               rc = lod_fld_lookup(env, lod, fid, &idx, &type);
+               if (!dt_object_exists(lo->ldo_stripe[i]))
+                       continue;
+
+               rc = lod_sub_xattr_set(env, lo->ldo_stripe[i], &slave_buf,
+                                      XATTR_NAME_LMV, fl, th);
                if (rc)
-                       GOTO(out, rc);
+                       break;
+       }
 
-               if (idx == lod2lu_dev(lod)->ld_site->ld_seq_site->ss_node_id) {
-                       tgt_dt = lod->lod_child;
-               } else {
-                       tgt = LTD_TGT(ltd, idx);
-                       if (tgt == NULL)
-                               GOTO(out, rc = -ESTALE);
-                       tgt_dt = tgt->ltd_tgt;
-               }
+       OBD_FREE_PTR(slave_lmv);
 
-               dto = dt_locate_at(env, tgt_dt, fid,
-                                 lo->ldo_obj.do_lu.lo_dev->ld_site->ls_top_dev,
-                                 NULL);
-               if (IS_ERR(dto))
-                       GOTO(out, rc = PTR_ERR(dto));
+       RETURN(rc);
+}
 
-               stripe[i + lo->ldo_dir_stripe_count] = dto;
+/**
+ * Implementation of dt_object_operations::do_declare_xattr_set.
+ *
+ * Used with regular (non-striped) objects. Basically it
+ * initializes the striping information and applies the
+ * change to all the stripes.
+ *
+ * \see dt_object_operations::do_declare_xattr_set() in the API description
+ * for details.
+ */
+static int lod_dir_declare_xattr_set(const struct lu_env *env,
+                                    struct dt_object *dt,
+                                    const struct lu_buf *buf,
+                                    const char *name, int fl,
+                                    struct thandle *th)
+{
+       struct dt_object        *next = dt_object_child(dt);
+       struct lod_device       *d = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lod_object       *lo = lod_dt_obj(dt);
+       int                     i;
+       int                     rc;
+       ENTRY;
 
-               if (!dt_try_as_dir(env, dto))
-                       GOTO(out, rc = -ENOTDIR);
+       if (strcmp(name, XATTR_NAME_DEFAULT_LMV) == 0) {
+               struct lmv_user_md_v1 *lum;
 
-               rc = lod_sub_declare_ref_add(env, dto, th);
-               if (rc)
-                       GOTO(out, rc);
+               LASSERT(buf != NULL && buf->lb_buf != NULL);
+               lum = buf->lb_buf;
+               rc = lod_verify_md_striping(d, lum);
+               if (rc != 0)
+                       RETURN(rc);
+       } else if (strcmp(name, XATTR_NAME_LOV) == 0) {
+               rc = lod_verify_striping(env, d, lo, buf, false);
+               if (rc != 0)
+                       RETURN(rc);
+       }
 
-               rc = lod_sub_declare_insert(env, dto,
-                                           (const struct dt_rec *)rec,
-                                           (const struct dt_key *)dot, th);
-               if (rc)
-                       GOTO(out, rc);
+       rc = lod_sub_declare_xattr_set(env, next, buf, name, fl, th);
+       if (rc != 0)
+               RETURN(rc);
 
-               rc = lod_sub_declare_insert(env, dto,
-                                           (const struct dt_rec *)rec,
-                                           (const struct dt_key *)dotdot, th);
-               if (rc)
-                       GOTO(out, rc);
+       /* Note: Do not set LinkEA on sub-stripes, otherwise
+        * it will confuse the fid2path process(see mdt_path_current()).
+        * The linkEA between master and sub-stripes is set in
+        * lod_xattr_set_lmv(). */
+       if (strcmp(name, XATTR_NAME_LINK) == 0)
+               RETURN(0);
 
-               rc = lod_sub_declare_xattr_set(env, dto, buf,
-                                               XATTR_NAME_LMV, 0, th);
-               if (rc)
-                       GOTO(out, rc);
+       /* set xattr to each stripes, if needed */
+       rc = lod_striping_load(env, lo);
+       if (rc != 0)
+               RETURN(rc);
 
-               snprintf(stripe_name, sizeof(info->lti_key), DFID":%u",
-                        PFID(lu_object_fid(&dto->do_lu)),
-                        i + lo->ldo_dir_stripe_count);
+       if (lo->ldo_dir_stripe_count == 0)
+               RETURN(0);
 
-               sname = lod_name_get(env, stripe_name, strlen(stripe_name));
-               rc = linkea_links_new(&ldata, &info->lti_linkea_buf,
-                                     sname, lu_object_fid(&dt->do_lu));
-               if (rc)
-                       GOTO(out, rc);
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               if (!lo->ldo_stripe[i])
+                       continue;
 
-               linkea_buf.lb_buf = ldata.ld_buf->lb_buf;
-               linkea_buf.lb_len = ldata.ld_leh->leh_len;
-               rc = lod_sub_declare_xattr_set(env, dto, &linkea_buf,
-                                              XATTR_NAME_LINK, 0, th);
-               if (rc)
-                       GOTO(out, rc);
-
-               rc = lod_sub_declare_insert(env, next,
-                                           (const struct dt_rec *)rec,
-                                           (const struct dt_key *)stripe_name,
-                                           th);
-               if (rc)
-                       GOTO(out, rc);
-
-               rc = lod_sub_declare_ref_add(env, next, th);
-               if (rc)
-                       GOTO(out, rc);
-       }
-
-       if (lo->ldo_stripe)
-               OBD_FREE(lo->ldo_stripe,
-                        sizeof(*stripe) * lo->ldo_dir_stripes_allocated);
-       lo->ldo_stripe = stripe;
-       lo->ldo_dir_migrate_offset = lo->ldo_dir_stripe_count;
-       lo->ldo_dir_migrate_hash = le32_to_cpu(lmv->lmv_hash_type);
-       lo->ldo_dir_stripe_count += stripe_count;
-       lo->ldo_dir_stripes_allocated += stripe_count;
-       lo->ldo_dir_hash_type |= LMV_HASH_FLAG_MIGRATION;
-
-       RETURN(0);
-out:
-       i = lo->ldo_dir_stripe_count;
-       while (i < lo->ldo_dir_stripe_count + stripe_count && stripe[i])
-               dt_object_put(env, stripe[i++]);
-
-       OBD_FREE(stripe,
-                sizeof(*stripe) * (stripe_count + lo->ldo_dir_stripe_count));
-       RETURN(rc);
-}
-
-static int lod_dir_declare_layout_delete(const struct lu_env *env,
-                                        struct dt_object *dt,
-                                        const struct lu_buf *buf,
-                                        struct thandle *th)
-{
-       struct lod_thread_info *info = lod_env_info(env);
-       struct lod_object *lo = lod_dt_obj(dt);
-       struct dt_object *next = dt_object_child(dt);
-       struct lmv_user_md *lmu = buf->lb_buf;
-       __u32 final_stripe_count;
-       char *stripe_name = info->lti_key;
-       struct dt_object *dto;
-       int i;
-       int rc = 0;
-
-       if (!lmu)
-               return -EINVAL;
-
-       final_stripe_count = le32_to_cpu(lmu->lum_stripe_count);
-       if (final_stripe_count >= lo->ldo_dir_stripe_count)
-               return -EINVAL;
-
-       for (i = final_stripe_count; i < lo->ldo_dir_stripe_count; i++) {
-               dto = lo->ldo_stripe[i];
-               LASSERT(dto);
-
-               if (!dt_try_as_dir(env, dto))
-                       return -ENOTDIR;
-
-               rc = lod_sub_declare_delete(env, dto,
-                                           (const struct dt_key *)dot, th);
-               if (rc)
-                       return rc;
-
-               rc = lod_sub_declare_ref_del(env, dto, th);
-               if (rc)
-                       return rc;
-
-               rc = lod_sub_declare_delete(env, dto,
-                                       (const struct dt_key *)dotdot, th);
-               if (rc)
-                       return rc;
-
-               snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
-                        PFID(lu_object_fid(&dto->do_lu)), i);
-
-               rc = lod_sub_declare_delete(env, next,
-                                       (const struct dt_key *)stripe_name, th);
-               if (rc)
-                       return rc;
-
-               rc = lod_sub_declare_ref_del(env, next, th);
-               if (rc)
-                       return rc;
-       }
-
-       return 0;
-}
-
-/*
- * delete stripes from dir master object, the lum_stripe_count in argument is
- * the final stripe count, the stripes after that will be deleted, NB, they
- * are not destroyed, but deleted from it's parent namespace, this function
- * will be called in two places:
- * 1. mdd_migrate_create() delete stripes from source, and append them to
- *    target.
- * 2. mdd_dir_layout_shrink() delete stripes from source, and destroy them.
- */
-static int lod_dir_layout_delete(const struct lu_env *env,
-                                struct dt_object *dt,
-                                const struct lu_buf *buf,
-                                struct thandle *th)
-{
-       struct lod_thread_info *info = lod_env_info(env);
-       struct lod_object *lo = lod_dt_obj(dt);
-       struct dt_object *next = dt_object_child(dt);
-       struct lmv_user_md *lmu = buf->lb_buf;
-       __u32 final_stripe_count;
-       char *stripe_name = info->lti_key;
-       struct dt_object *dto;
-       int i;
-       int rc = 0;
-
-       ENTRY;
-
-       if (!lmu)
-               RETURN(-EINVAL);
-
-       final_stripe_count = le32_to_cpu(lmu->lum_stripe_count);
-       if (final_stripe_count >= lo->ldo_dir_stripe_count)
-               RETURN(-EINVAL);
-
-       for (i = final_stripe_count; i < lo->ldo_dir_stripe_count; i++) {
-               dto = lo->ldo_stripe[i];
-               LASSERT(dto);
-
-               rc = lod_sub_delete(env, dto,
-                                   (const struct dt_key *)dotdot, th);
-               if (rc)
-                       break;
-
-               snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
-                        PFID(lu_object_fid(&dto->do_lu)), i);
-
-               rc = lod_sub_delete(env, next,
-                                   (const struct dt_key *)stripe_name, th);
-               if (rc)
-                       break;
-
-               rc = lod_sub_ref_del(env, next, th);
-               if (rc)
-                       break;
-       }
-
-       lod_striping_free(env, lod_dt_obj(dt));
-
-       RETURN(rc);
-}
-
-/**
- * Implementation of dt_object_operations::do_declare_xattr_set.
- *
- * Used with regular (non-striped) objects. Basically it
- * initializes the striping information and applies the
- * change to all the stripes.
- *
- * \see dt_object_operations::do_declare_xattr_set() in the API description
- * for details.
- */
-static int lod_dir_declare_xattr_set(const struct lu_env *env,
-                                    struct dt_object *dt,
-                                    const struct lu_buf *buf,
-                                    const char *name, int fl,
-                                    struct thandle *th)
-{
-       struct dt_object        *next = dt_object_child(dt);
-       struct lod_device       *d = lu2lod_dev(dt->do_lu.lo_dev);
-       struct lod_object       *lo = lod_dt_obj(dt);
-       int                     i;
-       int                     rc;
-       ENTRY;
-
-       if (strcmp(name, XATTR_NAME_DEFAULT_LMV) == 0) {
-               struct lmv_user_md_v1 *lum;
-
-               LASSERT(buf != NULL && buf->lb_buf != NULL);
-               lum = buf->lb_buf;
-               rc = lod_verify_md_striping(d, lum);
-               if (rc != 0)
-                       RETURN(rc);
-       } else if (strcmp(name, XATTR_NAME_LOV) == 0) {
-               rc = lod_verify_striping(d, lo, buf, false);
-               if (rc != 0)
-                       RETURN(rc);
-       }
-
-       rc = lod_sub_declare_xattr_set(env, next, buf, name, fl, th);
-       if (rc != 0)
-               RETURN(rc);
-
-       /* Note: Do not set LinkEA on sub-stripes, otherwise
-        * it will confuse the fid2path process(see mdt_path_current()).
-        * The linkEA between master and sub-stripes is set in
-        * lod_xattr_set_lmv(). */
-       if (strcmp(name, XATTR_NAME_LINK) == 0)
-               RETURN(0);
-
-       /* set xattr to each stripes, if needed */
-       rc = lod_striping_load(env, lo);
-       if (rc != 0)
-               RETURN(rc);
-
-       if (lo->ldo_dir_stripe_count == 0)
-               RETURN(0);
-
-       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-               LASSERT(lo->ldo_stripe[i]);
+               if (!dt_object_exists(lo->ldo_stripe[i]))
+                       continue;
 
                rc = lod_sub_declare_xattr_set(env, lo->ldo_stripe[i],
                                               buf, name, fl, th);
@@ -2473,20 +2608,25 @@ lod_obj_stripe_replace_parent_fid_cb(const struct lu_env *env,
                return rc;
        }
 
-       filter_fid_le_to_cpu(ff, ff, sizeof(*ff));
-
        /*
-        * mdd_declare_migrate_create() declares this via source object because
-        * target is not ready yet, so declare anyway.
+        * locd_buf is set if it's called by dir migration, which doesn't check
+        * pfid and comp id.
         */
-       if (!data->locd_declare &&
-           lu_fid_eq(lu_object_fid(&lo->ldo_obj.do_lu), &ff->ff_parent) &&
-           ff->ff_layout.ol_comp_id == comp->llc_id)
-               return 0;
+       if (data->locd_buf) {
+               memset(ff, 0, sizeof(*ff));
+               ff->ff_parent = *(struct lu_fid *)data->locd_buf->lb_buf;
+       } else {
+               filter_fid_le_to_cpu(ff, ff, sizeof(*ff));
+
+               if (lu_fid_eq(lod_object_fid(lo), &ff->ff_parent) &&
+                   ff->ff_layout.ol_comp_id == comp->llc_id)
+                       return 0;
+
+               memset(ff, 0, sizeof(*ff));
+               ff->ff_parent = *lu_object_fid(&lo->ldo_obj.do_lu);
+       }
 
        /* rewrite filter_fid */
-       memset(ff, 0, sizeof(*ff));
-       ff->ff_parent = *lu_object_fid(&lo->ldo_obj.do_lu);
        ff->ff_parent.f_ver = stripe_idx;
        ff->ff_layout.ol_stripe_size = comp->llc_stripe_size;
        ff->ff_layout.ol_stripe_count = comp->llc_stripe_count;
@@ -2522,11 +2662,11 @@ lod_obj_stripe_replace_parent_fid_cb(const struct lu_env *env,
  */
 static int lod_replace_parent_fid(const struct lu_env *env,
                                  struct dt_object *dt,
+                                 const struct lu_buf *buf,
                                  struct thandle *th, bool declare)
 {
        struct lod_object *lo = lod_dt_obj(dt);
        struct lod_thread_info  *info = lod_env_info(env);
-       struct lu_buf *buf = &info->lti_buf;
        struct filter_fid *ff;
        struct lod_obj_stripe_cb_data data = { { 0 } };
        int rc;
@@ -2548,30 +2688,33 @@ static int lod_replace_parent_fid(const struct lu_env *env,
                        RETURN(rc);
        }
 
-       buf->lb_buf = info->lti_ea_store;
-       buf->lb_len = info->lti_ea_store_size;
-
        data.locd_declare = declare;
        data.locd_stripe_cb = lod_obj_stripe_replace_parent_fid_cb;
+       data.locd_buf = buf;
        rc = lod_obj_for_each_stripe(env, lo, th, &data);
 
        RETURN(rc);
 }
 
-inline __u16 lod_comp_entry_stripe_count(struct lod_object *lo,
-                                        struct lod_layout_component *entry,
-                                        bool is_dir)
+__u16 lod_comp_entry_stripe_count(struct lod_object *lo,
+                                 int comp_idx, bool is_dir)
 {
        struct lod_device *lod = lu2lod_dev(lod2lu_obj(lo)->lo_dev);
+       struct lod_layout_component *entry;
 
        if (is_dir)
                return  0;
-       else if (lod_comp_inited(entry))
+
+       entry = &lo->ldo_comp_entries[comp_idx];
+       if (lod_comp_inited(entry))
                return entry->llc_stripe_count;
        else if ((__u16)-1 == entry->llc_stripe_count)
-               return lod->lod_desc.ld_tgt_count;
+               return lod->lod_ost_count;
        else
-               return lod_get_stripe_count(lod, lo, entry->llc_stripe_count);
+               return lod_get_stripe_count(lod, lo, comp_idx,
+                                           entry->llc_stripe_count,
+                                           entry->llc_pattern &
+                                           LOV_PATTERN_OVERSTRIPING);
 }
 
 static int lod_comp_md_size(struct lod_object *lo, bool is_dir)
@@ -2579,7 +2722,7 @@ static int lod_comp_md_size(struct lod_object *lo, bool is_dir)
        int magic, size = 0, i;
        struct lod_layout_component *comp_entries;
        __u16 comp_cnt;
-       bool is_composite;
+       bool is_composite, is_foreign = false;
 
        if (is_dir) {
                comp_cnt = lo->ldo_def_striping->lds_def_comp_cnt;
@@ -2590,8 +2733,11 @@ static int lod_comp_md_size(struct lod_object *lo, bool is_dir)
                comp_cnt = lo->ldo_comp_cnt;
                comp_entries = lo->ldo_comp_entries;
                is_composite = lo->ldo_is_composite;
+               is_foreign = lo->ldo_is_foreign;
        }
 
+       if (is_foreign)
+               return lo->ldo_foreign_lov_size;
 
        LASSERT(comp_cnt != 0 && comp_entries != NULL);
        if (is_composite) {
@@ -2604,8 +2750,7 @@ static int lod_comp_md_size(struct lod_object *lo, bool is_dir)
                __u16 stripe_count;
 
                magic = comp_entries[i].llc_pool ? LOV_MAGIC_V3 : LOV_MAGIC_V1;
-               stripe_count = lod_comp_entry_stripe_count(lo, &comp_entries[i],
-                                                          is_dir);
+               stripe_count = lod_comp_entry_stripe_count(lo, i, is_dir);
                if (!is_dir && is_composite)
                        lod_comp_shrink_stripe_count(&comp_entries[i],
                                                     &stripe_count);
@@ -2636,14 +2781,14 @@ static int lod_declare_layout_add(const struct lu_env *env,
 {
        struct lod_thread_info  *info = lod_env_info(env);
        struct lod_layout_component *comp_array, *lod_comp, *old_array;
-       struct lod_device       *d = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lod_device *d = lu2lod_dev(dt->do_lu.lo_dev);
        struct dt_object *next = dt_object_child(dt);
-       struct lov_desc         *desc = &d->lod_desc;
-       struct lod_object       *lo = lod_dt_obj(dt);
-       struct lov_user_md_v3   *v3;
-       struct lov_comp_md_v1   *comp_v1 = buf->lb_buf;
-       __u32   magic;
-       int     i, rc, array_cnt, old_array_cnt;
+       struct lov_desc *desc = &d->lod_ost_descs.ltd_lov_desc;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lov_user_md_v3 *v3;
+       struct lov_comp_md_v1 *comp_v1 = buf->lb_buf;
+       __u32 magic;
+       int i, rc, array_cnt, old_array_cnt;
        ENTRY;
 
        LASSERT(lo->ldo_is_composite);
@@ -2651,7 +2796,7 @@ static int lod_declare_layout_add(const struct lu_env *env,
        if (lo->ldo_flr_state != LCM_FL_NONE)
                RETURN(-EBUSY);
 
-       rc = lod_verify_striping(d, lo, buf, false);
+       rc = lod_verify_striping(env, d, lo, buf, false);
        if (rc != 0)
                RETURN(rc);
 
@@ -2664,10 +2809,15 @@ static int lod_declare_layout_add(const struct lu_env *env,
        if (magic != LOV_USER_MAGIC_COMP_V1)
                RETURN(-EINVAL);
 
+       mutex_lock(&lo->ldo_layout_mutex);
+
        array_cnt = lo->ldo_comp_cnt + comp_v1->lcm_entry_count;
-       OBD_ALLOC(comp_array, sizeof(*comp_array) * array_cnt);
-       if (comp_array == NULL)
+       OBD_ALLOC_PTR_ARRAY(comp_array, array_cnt);
+       if (comp_array == NULL) {
+               mutex_unlock(&lo->ldo_layout_mutex);
                RETURN(-ENOMEM);
+       }
+
 
        memcpy(comp_array, lo->ldo_comp_entries,
               sizeof(*comp_array) * lo->ldo_comp_cnt);
@@ -2688,7 +2838,7 @@ static int lod_declare_layout_add(const struct lu_env *env,
 
                lod_comp->llc_stripe_count = v1->lmm_stripe_count;
                lod_comp->llc_stripe_size = v1->lmm_stripe_size;
-               lod_adjust_stripe_info(lod_comp, desc);
+               lod_adjust_stripe_info(lod_comp, desc, 0);
 
                if (v1->lmm_magic == LOV_USER_MAGIC_V3) {
                        v3 = (struct lov_user_md_v3 *) v1;
@@ -2719,11 +2869,13 @@ static int lod_declare_layout_add(const struct lu_env *env,
                GOTO(error, rc);
        }
 
-       OBD_FREE(old_array, sizeof(*lod_comp) * old_array_cnt);
+       OBD_FREE_PTR_ARRAY(old_array, old_array_cnt);
 
        LASSERT(lo->ldo_mirror_count == 1);
        lo->ldo_mirrors[0].lme_end = array_cnt - 1;
 
+       mutex_unlock(&lo->ldo_layout_mutex);
+
        RETURN(0);
 
 error:
@@ -2735,15 +2887,55 @@ error:
                        lod_comp->llc_pool = NULL;
                }
        }
-       OBD_FREE(comp_array, sizeof(*comp_array) * array_cnt);
+       OBD_FREE_PTR_ARRAY(comp_array, array_cnt);
+       mutex_unlock(&lo->ldo_layout_mutex);
+
        RETURN(rc);
 }
 
 /**
+ * lod_last_non_stale_mirror() - Check if a mirror is the last non-stale mirror.
+ * @mirror_id: Mirror id to be checked.
+ * @lo:        LOD object.
+ *
+ * This function checks if a mirror with specified @mirror_id is the last
+ * non-stale mirror of a LOD object @lo.
+ *
+ * Return: true or false.
+ */
+static inline
+bool lod_last_non_stale_mirror(__u16 mirror_id, struct lod_object *lo)
+{
+       struct lod_layout_component *lod_comp;
+       bool has_stale_flag;
+       int i;
+
+       for (i = 0; i < lo->ldo_mirror_count; i++) {
+               if (lo->ldo_mirrors[i].lme_id == mirror_id ||
+                   lo->ldo_mirrors[i].lme_stale)
+                       continue;
+
+               has_stale_flag = false;
+               lod_foreach_mirror_comp(lod_comp, lo, i) {
+                       if (lod_comp->llc_flags & LCME_FL_STALE) {
+                               has_stale_flag = true;
+                               break;
+                       }
+               }
+               if (!has_stale_flag)
+                       return false;
+       }
+
+       return true;
+}
+
+/**
  * Declare component set. The xattr is name XATTR_LUSTRE_LOV.set.$field,
  * the '$field' can only be 'flags' now. The xattr value is binary
  * lov_comp_md_v1 which contains the component ID(s) and the value of
  * the field to be modified.
+ * Please update allowed_lustre_lov macro if $field groks more values
+ * in the future.
  *
  * \param[in] env      execution environment
  * \param[in] dt       dt_object to be modified
@@ -2769,6 +2961,9 @@ static int lod_declare_layout_set(const struct lu_env *env,
        bool    changed = false;
        ENTRY;
 
+       /* Please update allowed_lustre_lov macro if op
+        * groks more values in the future
+        */
        if (strcmp(op, "set.flags") != 0) {
                CDEBUG(D_LAYOUT, "%s: operation (%s) not supported.\n",
                       lod2obd(d)->obd_name, op);
@@ -2790,30 +2985,58 @@ static int lod_declare_layout_set(const struct lu_env *env,
                RETURN(-EINVAL);
        }
 
+       mutex_lock(&lo->ldo_layout_mutex);
        for (i = 0; i < comp_v1->lcm_entry_count; i++) {
                __u32 id = comp_v1->lcm_entries[i].lcme_id;
                __u32 flags = comp_v1->lcm_entries[i].lcme_flags;
+               __u32 mirror_flag = flags & LCME_MIRROR_FLAGS;
+               __u16 mirror_id = mirror_id_of(id);
+               bool neg = flags & LCME_FL_NEG;
 
                if (flags & LCME_FL_INIT) {
                        if (changed)
-                               lod_striping_free(env, lo);
+                               lod_striping_free_nolock(env, lo);
+                       mutex_unlock(&lo->ldo_layout_mutex);
                        RETURN(-EINVAL);
                }
 
+               flags &= ~(LCME_MIRROR_FLAGS | LCME_FL_NEG);
                for (j = 0; j < lo->ldo_comp_cnt; j++) {
                        lod_comp = &lo->ldo_comp_entries[j];
-                       if (id != lod_comp->llc_id)
+
+                       /* lfs only put one flag in each entry */
+                       if ((flags && id != lod_comp->llc_id) ||
+                           (mirror_flag && mirror_id !=
+                                           mirror_id_of(lod_comp->llc_id)))
                                continue;
 
-                       if (flags & LCME_FL_NEG) {
-                               flags &= ~LCME_FL_NEG;
-                               lod_comp->llc_flags &= ~flags;
+                       if (neg) {
+                               if (flags)
+                                       lod_comp->llc_flags &= ~flags;
+                               if (mirror_flag)
+                                       lod_comp->llc_flags &= ~mirror_flag;
                        } else {
-                               lod_comp->llc_flags |= flags;
+                               if (flags) {
+                                       if ((flags & LCME_FL_STALE) &&
+                                           lod_last_non_stale_mirror(mirror_id,
+                                                                     lo)) {
+                                               mutex_unlock(
+                                                       &lo->ldo_layout_mutex);
+                                               RETURN(-EUCLEAN);
+                                       }
+                                       lod_comp->llc_flags |= flags;
+                               }
+                               if (mirror_flag) {
+                                       lod_comp->llc_flags |= mirror_flag;
+                                       if (mirror_flag & LCME_FL_NOSYNC)
+                                               lod_comp->llc_timestamp =
+                                                      ktime_get_real_seconds();
+                               }
                        }
                        changed = true;
                }
        }
+       mutex_unlock(&lo->ldo_layout_mutex);
 
        if (!changed) {
                CDEBUG(D_LAYOUT, "%s: requested component(s) not found.\n",
@@ -2896,9 +3119,13 @@ static int lod_declare_layout_del(const struct lu_env *env,
                flags = 0;
        }
 
+       mutex_lock(&lo->ldo_layout_mutex);
+
        left = lo->ldo_comp_cnt;
-       if (left <= 0)
+       if (left <= 0) {
+               mutex_unlock(&lo->ldo_layout_mutex);
                RETURN(-EINVAL);
+       }
 
        for (i = (lo->ldo_comp_cnt - 1); i >= 0; i--) {
                struct lod_layout_component *lod_comp;
@@ -2915,6 +3142,7 @@ static int lod_declare_layout_del(const struct lu_env *env,
                if (left != (i + 1)) {
                        CDEBUG(D_LAYOUT, "%s: this deletion will create "
                               "a hole.\n", lod2obd(d)->obd_name);
+                       mutex_unlock(&lo->ldo_layout_mutex);
                        RETURN(-EINVAL);
                }
                left--;
@@ -2933,8 +3161,10 @@ static int lod_declare_layout_del(const struct lu_env *env,
                        if (obj == NULL)
                                continue;
                        rc = lod_sub_declare_destroy(env, obj, th);
-                       if (rc)
+                       if (rc) {
+                               mutex_unlock(&lo->ldo_layout_mutex);
                                RETURN(rc);
+                       }
                }
        }
 
@@ -2942,9 +3172,12 @@ static int lod_declare_layout_del(const struct lu_env *env,
        if (left == lo->ldo_comp_cnt) {
                CDEBUG(D_LAYOUT, "%s: requested component id:%#x not found\n",
                       lod2obd(d)->obd_name, id);
+               mutex_unlock(&lo->ldo_layout_mutex);
                RETURN(-EINVAL);
        }
 
+       mutex_unlock(&lo->ldo_layout_mutex);
+
        memset(attr, 0, sizeof(*attr));
        attr->la_valid = LA_SIZE;
        rc = lod_sub_declare_attr_set(env, next, attr, th);
@@ -3066,13 +3299,13 @@ static int lod_layout_convert(struct lod_thread_info *info)
        }
 
        lcm = info->lti_ea_store;
+       memset(lcm, 0, sizeof(*lcm) + sizeof(*lcme));
        lcm->lcm_magic = cpu_to_le32(LOV_MAGIC_COMP_V1);
        lcm->lcm_size = cpu_to_le32(size);
        lcm->lcm_layout_gen = cpu_to_le32(le16_to_cpu(
                                                lmm_save->lmm_layout_gen));
        lcm->lcm_flags = cpu_to_le16(LCM_FL_NONE);
        lcm->lcm_entry_count = cpu_to_le16(1);
-       lcm->lcm_mirror_count = 0;
 
        lcme = &lcm->lcm_entries[0];
        lcme->lcme_flags = cpu_to_le32(LCME_FL_INIT);
@@ -3097,13 +3330,15 @@ static int lod_declare_layout_merge(const struct lu_env *env,
                struct dt_object *dt, const struct lu_buf *mbuf,
                struct thandle *th)
 {
-       struct lod_thread_info  *info = lod_env_info(env);
-       struct lu_buf           *buf = &info->lti_buf;
-       struct lod_object       *lo = lod_dt_obj(dt);
-       struct lov_comp_md_v1   *lcm;
-       struct lov_comp_md_v1   *cur_lcm;
-       struct lov_comp_md_v1   *merge_lcm;
-       struct lov_comp_md_entry_v1     *lcme;
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lu_attr *layout_attr = &info->lti_layout_attr;
+       struct lu_buf *buf = &info->lti_buf;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lov_comp_md_v1 *lcm;
+       struct lov_comp_md_v1 *cur_lcm;
+       struct lov_comp_md_v1 *merge_lcm;
+       struct lov_comp_md_entry_v1 *lcme;
+       struct lov_mds_md_v1 *lmm;
        size_t size = 0;
        size_t offset;
        __u16 cur_entry_count;
@@ -3111,7 +3346,9 @@ static int lod_declare_layout_merge(const struct lu_env *env,
        __u32 id = 0;
        __u16 mirror_id = 0;
        __u32 mirror_count;
-       int     rc, i;
+       int rc, i;
+       bool merge_has_dom;
+
        ENTRY;
 
        merge_lcm = mbuf->lb_buf;
@@ -3140,6 +3377,7 @@ static int lod_declare_layout_merge(const struct lu_env *env,
                rc = lod_layout_convert(info);
                break;
        case LOV_MAGIC_COMP_V1:
+       case LOV_MAGIC_SEL:
                rc = 0;
                break;
        default:
@@ -3194,10 +3432,17 @@ static int lod_declare_layout_merge(const struct lu_env *env,
                        lcme->lcme_id = cpu_to_le32(id);
                }
 
-               id = MAX(le32_to_cpu(lcme->lcme_id), id);
+               id = max(le32_to_cpu(lcme->lcme_id), id);
        }
 
        mirror_id = mirror_id_of(id) + 1;
+
+       /* check if first entry in new layout is DOM */
+       lmm = (struct lov_mds_md_v1 *)((char *)merge_lcm +
+                                       merge_lcm->lcm_entries[0].lcme_offset);
+       merge_has_dom = lov_pattern(le32_to_cpu(lmm->lmm_pattern)) ==
+                       LOV_PATTERN_MDT;
+
        for (i = 0; i < merge_entry_count; i++) {
                struct lov_comp_md_entry_v1 *merge_lcme;
 
@@ -3206,6 +3451,8 @@ static int lod_declare_layout_merge(const struct lu_env *env,
 
                *lcme = *merge_lcme;
                lcme->lcme_offset = cpu_to_le32(offset);
+               if (merge_has_dom && i == 0)
+                       lcme->lcme_flags |= cpu_to_le32(LCME_FL_STALE);
 
                id = pflr_id(mirror_id, i + 1);
                lcme->lcme_id = cpu_to_le32(id);
@@ -3218,18 +3465,33 @@ static int lod_declare_layout_merge(const struct lu_env *env,
        }
 
        /* fixup layout information */
-       lod_obj_inc_layout_gen(lo);
-       lcm->lcm_layout_gen = cpu_to_le32(lo->ldo_layout_gen);
        lcm->lcm_size = cpu_to_le32(size);
        lcm->lcm_entry_count = cpu_to_le16(cur_entry_count + merge_entry_count);
        lcm->lcm_mirror_count = cpu_to_le16(mirror_count);
        if ((le16_to_cpu(lcm->lcm_flags) & LCM_FL_FLR_MASK) == LCM_FL_NONE)
                lcm->lcm_flags = cpu_to_le32(LCM_FL_RDONLY);
 
-       rc = lod_striping_reload(env, lo, buf);
+       rc = lod_striping_reload(env, lo, buf, 0);
        if (rc)
                GOTO(out, rc);
 
+       lod_obj_inc_layout_gen(lo);
+       lcm->lcm_layout_gen = cpu_to_le32(lo->ldo_layout_gen);
+
+       /* transfer layout version to OST objects. */
+       if (lo->ldo_mirror_count > 1) {
+               struct lod_obj_stripe_cb_data data = { {0} };
+
+               layout_attr->la_valid = LA_LAYOUT_VERSION;
+               layout_attr->la_layout_version = 0;
+               data.locd_attr = layout_attr;
+               data.locd_declare = true;
+               data.locd_stripe_cb = lod_obj_stripe_attr_set_cb;
+               rc = lod_obj_for_each_stripe(env, lo, th, &data);
+               if (rc)
+                       GOTO(out, rc);
+       }
+
        rc = lod_sub_declare_xattr_set(env, dt_object_child(dt), buf,
                                        XATTR_NAME_LOV, LU_XATTR_REPLACE, th);
 
@@ -3245,23 +3507,231 @@ static int lod_declare_layout_split(const struct lu_env *env,
                struct dt_object *dt, const struct lu_buf *mbuf,
                struct thandle *th)
 {
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lu_attr *layout_attr = &info->lti_layout_attr;
        struct lod_object *lo = lod_dt_obj(dt);
        struct lov_comp_md_v1 *lcm = mbuf->lb_buf;
        int rc;
        ENTRY;
 
+       rc = lod_striping_reload(env, lo, mbuf, LVF_ALL_STALE);
+       if (rc)
+               RETURN(rc);
+
        lod_obj_inc_layout_gen(lo);
+       /* fix on-disk layout gen */
        lcm->lcm_layout_gen = cpu_to_le32(lo->ldo_layout_gen);
 
-       rc = lod_striping_reload(env, lo, mbuf);
-       if (rc)
-               RETURN(rc);
+
+       /* transfer layout version to OST objects. */
+       if (lo->ldo_mirror_count > 1) {
+               struct lod_obj_stripe_cb_data data = { {0} };
+
+               layout_attr->la_valid = LA_LAYOUT_VERSION;
+               layout_attr->la_layout_version = 0;
+               data.locd_attr = layout_attr;
+               data.locd_declare = true;
+               data.locd_stripe_cb = lod_obj_stripe_attr_set_cb;
+               rc = lod_obj_for_each_stripe(env, lo, th, &data);
+               if (rc)
+                       RETURN(rc);
+       }
 
        rc = lod_sub_declare_xattr_set(env, dt_object_child(dt), mbuf,
                                       XATTR_NAME_LOV, LU_XATTR_REPLACE, th);
        RETURN(rc);
 }
 
+static int lod_layout_declare_or_purge_mirror(const struct lu_env *env,
+                       struct dt_object *dt, const struct lu_buf *buf,
+                       struct thandle *th, bool declare)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_device *d = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lov_comp_md_v1 *comp_v1 = buf->lb_buf;
+       struct lov_comp_md_entry_v1 *entry;
+       struct lov_mds_md_v1 *lmm;
+       struct dt_object **sub_objs = NULL;
+       int rc = 0, i, k, array_count = 0;
+
+       ENTRY;
+
+       /**
+        * other ops (like lod_declare_destroy) could destroying sub objects
+        * as well.
+        */
+       mutex_lock(&lo->ldo_layout_mutex);
+
+       if (!declare) {
+               /* prepare sub-objects array */
+               for (i = 0; i < comp_v1->lcm_entry_count; i++) {
+                       entry = &comp_v1->lcm_entries[i];
+
+                       if (!(entry->lcme_flags & LCME_FL_INIT))
+                               continue;
+
+                       lmm = (struct lov_mds_md_v1 *)
+                                       ((char *)comp_v1 + entry->lcme_offset);
+                       array_count += lmm->lmm_stripe_count;
+               }
+               OBD_ALLOC_PTR_ARRAY(sub_objs, array_count);
+               if (sub_objs == NULL) {
+                       mutex_unlock(&lo->ldo_layout_mutex);
+                       RETURN(-ENOMEM);
+               }
+       }
+
+       k = 0;  /* sub_objs index */
+       for (i = 0; i < comp_v1->lcm_entry_count; i++) {
+               struct lov_ost_data_v1 *objs;
+               struct lu_object *o, *n;
+               struct dt_object *dto;
+               struct lu_device *nd;
+               struct lov_mds_md_v3 *v3;
+               __u32 idx;
+               int j;
+
+               entry = &comp_v1->lcm_entries[i];
+
+               if (!(entry->lcme_flags & LCME_FL_INIT))
+                       continue;
+
+               lmm = (struct lov_mds_md_v1 *)
+                               ((char *)comp_v1 + entry->lcme_offset);
+               v3 = (struct lov_mds_md_v3 *)lmm;
+               if (lmm->lmm_magic == LOV_MAGIC_V3)
+                       objs = &v3->lmm_objects[0];
+               else
+                       objs = &lmm->lmm_objects[0];
+
+               for (j = 0; j < lmm->lmm_stripe_count; j++) {
+                       idx = objs[j].l_ost_idx;
+                       rc = ostid_to_fid(&info->lti_fid, &objs[j].l_ost_oi,
+                                         idx);
+                       if (rc)
+                               GOTO(out, rc);
+
+                       if (!fid_is_sane(&info->lti_fid)) {
+                               CERROR("%s: sub-object insane fid "DFID"\n",
+                                      lod2obd(d)->obd_name,
+                                      PFID(&info->lti_fid));
+                               GOTO(out, rc = -EINVAL);
+                       }
+
+                       lod_getref(&d->lod_ost_descs);
+
+                       rc = validate_lod_and_idx(d, idx);
+                       if (unlikely(rc)) {
+                               lod_putref(d, &d->lod_ost_descs);
+                               GOTO(out, rc);
+                       }
+
+                       nd = &OST_TGT(d, idx)->ltd_tgt->dd_lu_dev;
+                       lod_putref(d, &d->lod_ost_descs);
+
+                       o = lu_object_find_at(env, nd, &info->lti_fid, NULL);
+                       if (IS_ERR(o))
+                               GOTO(out, rc = PTR_ERR(o));
+
+                       n = lu_object_locate(o->lo_header, nd->ld_type);
+                       if (unlikely(!n)) {
+                               lu_object_put(env, n);
+                               GOTO(out, rc = -ENOENT);
+                       }
+
+                       dto = container_of(n, struct dt_object, do_lu);
+
+                       if (declare) {
+                               rc = lod_sub_declare_destroy(env, dto, th);
+                               dt_object_put(env, dto);
+                               if (rc)
+                                       GOTO(out, rc);
+                       } else {
+                               /**
+                                * collect to-be-destroyed sub objects, the
+                                * reference would be released after actual
+                                * deletion.
+                                */
+                               sub_objs[k] = dto;
+                               k++;
+                       }
+               } /* for each stripe */
+       } /* for each component in the mirror */
+out:
+       if (!declare) {
+               i = 0;
+               if (!rc) {
+                       /* destroy the sub objects */
+                       for (; i < k; i++) {
+                               rc = lod_sub_destroy(env, sub_objs[i], th);
+                               if (rc)
+                                       break;
+                               dt_object_put(env, sub_objs[i]);
+                       }
+               }
+               /**
+                * if a sub object destroy failed, we'd release sub objects
+                * reference get from above sub_objs collection.
+                */
+               for (; i < k; i++)
+                       dt_object_put(env, sub_objs[i]);
+
+               OBD_FREE_PTR_ARRAY(sub_objs, array_count);
+       }
+       mutex_unlock(&lo->ldo_layout_mutex);
+
+       RETURN(rc);
+}
+
+/**
+ * Purge layouts, delete sub objects in the mirror stored in the vic_buf,
+ * and set the LOVEA with the layout from mbuf.
+ */
+static int lod_declare_layout_purge(const struct lu_env *env,
+               struct dt_object *dt, const struct lu_buf *buf,
+               struct thandle *th)
+{
+       struct lod_device *d = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lov_comp_md_v1 *comp_v1 = buf->lb_buf;
+       int rc;
+
+       ENTRY;
+
+       if (le32_to_cpu(comp_v1->lcm_magic) != LOV_MAGIC_COMP_V1) {
+               CERROR("%s: invalid layout magic %#x != %#x\n",
+                      lod2obd(d)->obd_name, le32_to_cpu(comp_v1->lcm_magic),
+                      LOV_MAGIC_COMP_V1);
+               RETURN(-EINVAL);
+       }
+
+       if (cpu_to_le32(LOV_MAGIC_COMP_V1) != LOV_MAGIC_COMP_V1)
+               lustre_swab_lov_comp_md_v1(comp_v1);
+
+       /* from now on, @buf contains cpu endian data */
+
+       if (comp_v1->lcm_mirror_count != 0) {
+               CERROR("%s: can only purge one mirror from "DFID"\n",
+                      lod2obd(d)->obd_name, PFID(lu_object_fid(&dt->do_lu)));
+               RETURN(-EINVAL);
+       }
+
+       /* delcare sub objects deletion in the mirror stored in @buf */
+       rc = lod_layout_declare_or_purge_mirror(env, dt, buf, th, true);
+       RETURN(rc);
+}
+
+/* delete sub objects from the mirror stored in @buf */
+static int lod_layout_purge(const struct lu_env *env, struct dt_object *dt,
+                           const struct lu_buf *buf, struct thandle *th)
+{
+       int rc;
+
+       ENTRY;
+       rc = lod_layout_declare_or_purge_mirror(env, dt, buf, th, false);
+       RETURN(rc);
+}
+
 /**
  * Implementation of dt_object_operations::do_declare_xattr_set.
  *
@@ -3286,7 +3756,8 @@ static int lod_declare_xattr_set(const struct lu_env *env,
 
        mode = dt->do_lu.lo_header->loh_attr & S_IFMT;
        if ((S_ISREG(mode) || mode == 0) &&
-           !(fl & (LU_XATTR_REPLACE | LU_XATTR_MERGE | LU_XATTR_SPLIT)) &&
+           !(fl & (LU_XATTR_REPLACE | LU_XATTR_MERGE | LU_XATTR_SPLIT |
+                   LU_XATTR_PURGE)) &&
            (strcmp(name, XATTR_NAME_LOV) == 0 ||
             strcmp(name, XATTR_LUSTRE_LOV) == 0)) {
                /*
@@ -3316,10 +3787,13 @@ static int lod_declare_xattr_set(const struct lu_env *env,
                LASSERT(strcmp(name, XATTR_NAME_LOV) == 0 ||
                        strcmp(name, XATTR_LUSTRE_LOV) == 0);
                rc = lod_declare_layout_split(env, dt, buf, th);
+       } else if (fl & LU_XATTR_PURGE) {
+               LASSERT(strcmp(name, XATTR_NAME_LOV) == 0 ||
+                       strcmp(name, XATTR_LUSTRE_LOV) == 0);
+               rc = lod_declare_layout_purge(env, dt, buf, th);
        } else if (S_ISREG(mode) &&
-                  strlen(name) > strlen(XATTR_LUSTRE_LOV) + 1 &&
-                  strncmp(name, XATTR_LUSTRE_LOV,
-                          strlen(XATTR_LUSTRE_LOV)) == 0) {
+                  strlen(name) >= sizeof(XATTR_LUSTRE_LOV) + 3 &&
+                  allowed_lustre_lov(name)) {
                /*
                 * this is a request to modify object's striping.
                 * add/set/del component(s).
@@ -3328,21 +3802,10 @@ static int lod_declare_xattr_set(const struct lu_env *env,
                        RETURN(-ENOENT);
 
                rc = lod_declare_modify_layout(env, dt, name, buf, th);
-       } else if (strncmp(name, XATTR_NAME_LMV, strlen(XATTR_NAME_LMV)) == 0 &&
-                  strlen(name) > strlen(XATTR_NAME_LMV) + 1) {
-               const char *op = name + strlen(XATTR_NAME_LMV) + 1;
-
-               rc = -ENOTSUPP;
-               if (strcmp(op, "add") == 0)
-                       rc = lod_dir_declare_layout_add(env, dt, buf, th);
-               else if (strcmp(op, "del") == 0)
-                       rc = lod_dir_declare_layout_delete(env, dt, buf, th);
-
-               RETURN(rc);
        } else if (S_ISDIR(mode)) {
                rc = lod_dir_declare_xattr_set(env, dt, buf, name, fl, th);
        } else if (strcmp(name, XATTR_NAME_FID) == 0) {
-               rc = lod_replace_parent_fid(env, dt, th, true);
+               rc = lod_replace_parent_fid(env, dt, buf, th, true);
        } else {
                rc = lod_sub_declare_xattr_set(env, next, buf, name, fl, th);
        }
@@ -3389,7 +3852,11 @@ static int lod_xattr_set_internal(const struct lu_env *env,
                RETURN(0);
 
        for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-               LASSERT(lo->ldo_stripe[i]);
+               if (!lo->ldo_stripe[i])
+                       continue;
+
+               if (!dt_object_exists(lo->ldo_stripe[i]))
+                       continue;
 
                rc = lod_sub_xattr_set(env, lo->ldo_stripe[i], buf, name,
                                       fl, th);
@@ -3417,10 +3884,11 @@ static int lod_xattr_del_internal(const struct lu_env *env,
                                  struct dt_object *dt,
                                  const char *name, struct thandle *th)
 {
-       struct dt_object        *next = dt_object_child(dt);
-       struct lod_object       *lo = lod_dt_obj(dt);
-       int                     rc;
-       int                     i;
+       struct dt_object *next = dt_object_child(dt);
+       struct lod_object *lo = lod_dt_obj(dt);
+       int i;
+       int rc;
+
        ENTRY;
 
        rc = lod_sub_xattr_del(env, next, name, th);
@@ -3431,7 +3899,11 @@ static int lod_xattr_del_internal(const struct lu_env *env,
                RETURN(rc);
 
        for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-               LASSERT(lo->ldo_stripe[i]);
+               if (!lo->ldo_stripe[i])
+                       continue;
+
+               if (!dt_object_exists(lo->ldo_stripe[i]))
+                       continue;
 
                rc = lod_sub_xattr_del(env, lo->ldo_stripe[i], name, th);
                if (rc != 0)
@@ -3481,7 +3953,7 @@ static int lod_xattr_set_lov_on_dir(const struct lu_env *env,
                v3 = buf->lb_buf;
                if (v3->lmm_pool_name[0] != '\0')
                        pool_name = v3->lmm_pool_name;
-               /* fall through */
+               fallthrough;
        case LOV_USER_MAGIC_V1:
                /* if { size, offset, count } = { 0, -1, 0 } and no pool
                 * (i.e. all default values specified) then delete default
@@ -3499,8 +3971,23 @@ static int lod_xattr_set_lov_on_dir(const struct lu_env *env,
                                             pool_name);
                break;
        case LOV_USER_MAGIC_COMP_V1:
+       {
+               struct lov_comp_md_v1 *lcm = (struct lov_comp_md_v1 *)lum;
+               struct lov_comp_md_entry_v1 *lcme;
+               int i, comp_cnt;
+
+               comp_cnt = le16_to_cpu(lcm->lcm_entry_count);
+               for (i = 0; i < comp_cnt; i++) {
+                       lcme = &lcm->lcm_entries[i];
+                       if (lcme->lcme_flags & cpu_to_le32(LCME_FL_EXTENSION)) {
+                               lcm->lcm_magic = cpu_to_le32(LOV_MAGIC_SEL);
+                               break;
+                       }
+               }
+
                is_del = false;
                break;
+       }
        default:
                CERROR("Invalid magic %x\n", lum->lmm_magic);
                RETURN(-EINVAL);
@@ -3517,6 +4004,192 @@ static int lod_xattr_set_lov_on_dir(const struct lu_env *env,
        RETURN(rc);
 }
 
+static int lod_get_default_lov_striping(const struct lu_env *env,
+                                      struct lod_object *lo,
+                                      struct lod_default_striping *lds,
+                                      struct dt_allocation_hint *ah);
+
+/**
+ * Helper function to convert compound layout to compound layout with
+ * pool
+ *
+ * Copy lcm_entries array of \a src to \a tgt. Replace lov_user_md_v1
+ * components of \a src with lov_user_md_v3 using \a pool.
+ *
+ * \param[in] src      source layout
+ * \param[in] pool     pool to use in \a tgt
+ * \param[out] tgt     target layout
+ */
+static void embed_pool_to_comp_v1(const struct lov_comp_md_v1 *src,
+                                 const char *pool,
+                                 struct lov_comp_md_v1 *tgt)
+{
+       size_t shift;
+       struct lov_user_md_v1 *lum;
+       struct lov_user_md_v3 *lum3;
+       struct lov_comp_md_entry_v1 *entry;
+       int i;
+       __u32 offset;
+
+       entry = tgt->lcm_entries;
+       shift = 0;
+       for (i = 0; i < le16_to_cpu(src->lcm_entry_count); i++, entry++) {
+               *entry = src->lcm_entries[i];
+               offset = le32_to_cpu(src->lcm_entries[i].lcme_offset);
+               entry->lcme_offset = cpu_to_le32(offset + shift);
+
+               lum = (struct lov_user_md_v1 *)((char *)src + offset);
+               lum3 = (struct lov_user_md_v3 *)((char *)tgt + offset + shift);
+               *(struct lov_user_md_v1 *)lum3 = *lum;
+               if (lum->lmm_pattern == cpu_to_le32(LOV_PATTERN_MDT)) {
+                       lum3->lmm_magic = cpu_to_le32(LOV_USER_MAGIC_V1);
+               } else {
+                       lum3->lmm_magic = cpu_to_le32(LOV_USER_MAGIC_V3);
+                       entry->lcme_size = cpu_to_le32(sizeof(*lum3));
+                       strlcpy(lum3->lmm_pool_name, pool,
+                               sizeof(lum3->lmm_pool_name));
+                       shift += sizeof(*lum3) - sizeof(*lum);
+               }
+       }
+}
+
+/**
+ * Set default striping on a directory.
+ *
+ * Sets specified striping on a directory object unless it matches the default
+ * striping (LOVEA_DELETE_VALUES() macro). In the latter case remove existing
+ * EA. This striping will be used when regular file is being created in this
+ * directory.
+ * If current default striping includes a pool but specifed striping
+ * does not - retain the pool if it exists.
+ *
+ * \param[in] env      execution environment
+ * \param[in] dt       the striped object
+ * \param[in] buf      buffer with the striping
+ * \param[in] name     name of EA
+ * \param[in] fl       xattr flag (see OSD API description)
+ * \param[in] th       transaction handle
+ *
+ * \retval             0 on success
+ * \retval             negative if failed
+ */
+static int lod_xattr_set_default_lov_on_dir(const struct lu_env *env,
+                                           struct dt_object *dt,
+                                           const struct lu_buf *buf,
+                                           const char *name, int fl,
+                                           struct thandle *th)
+{
+       struct lod_default_striping     *lds = lod_lds_buf_get(env);
+       struct lov_user_md_v1           *v1 = buf->lb_buf;
+       char                             pool[LOV_MAXPOOLNAME + 1];
+       bool                             is_del;
+       int                              rc;
+
+       ENTRY;
+
+       /* get existing striping config */
+       rc = lod_get_default_lov_striping(env, lod_dt_obj(dt), lds, NULL);
+       if (rc)
+               RETURN(rc);
+
+       memset(pool, 0, sizeof(pool));
+       if (lds->lds_def_striping_set == 1)
+               lod_layout_get_pool(lds->lds_def_comp_entries,
+                                   lds->lds_def_comp_cnt, pool,
+                                   sizeof(pool));
+
+       is_del = LOVEA_DELETE_VALUES(v1->lmm_stripe_size,
+                                    v1->lmm_stripe_count,
+                                    v1->lmm_stripe_offset,
+                                    NULL);
+
+       /* Retain the pool name if it is not given */
+       if (v1->lmm_magic == LOV_USER_MAGIC_V1 && pool[0] != '\0' &&
+           !is_del) {
+               struct lod_thread_info *info = lod_env_info(env);
+               struct lov_user_md_v3 *v3  = info->lti_ea_store;
+
+               memset(v3, 0, sizeof(*v3));
+               v3->lmm_magic = cpu_to_le32(LOV_USER_MAGIC_V3);
+               v3->lmm_pattern = cpu_to_le32(v1->lmm_pattern);
+               v3->lmm_stripe_count = cpu_to_le32(v1->lmm_stripe_count);
+               v3->lmm_stripe_offset = cpu_to_le32(v1->lmm_stripe_offset);
+               v3->lmm_stripe_size = cpu_to_le32(v1->lmm_stripe_size);
+
+               strlcpy(v3->lmm_pool_name, pool, sizeof(v3->lmm_pool_name));
+
+               info->lti_buf.lb_buf = v3;
+               info->lti_buf.lb_len = sizeof(*v3);
+               rc = lod_xattr_set_lov_on_dir(env, dt, &info->lti_buf,
+                                             name, fl, th);
+       } else if (v1->lmm_magic == LOV_USER_MAGIC_COMP_V1 &&
+                  pool[0] != '\0' && !is_del) {
+               /*
+                * try to retain the pool from default layout if the
+                * specified component layout does not provide pool
+                * info explicitly
+                */
+               struct lod_thread_info *info = lod_env_info(env);
+               struct lov_comp_md_v1 *comp_v1 = buf->lb_buf;
+               struct lov_comp_md_v1 *comp_v1p;
+               struct lov_user_md_v1 *lum;
+               int entry_count;
+               int i;
+               __u32 offset;
+               struct lov_comp_md_entry_v1 *entry;
+               int size;
+
+               entry_count = le16_to_cpu(comp_v1->lcm_entry_count);
+               size = sizeof(*comp_v1) +
+                       entry_count * sizeof(comp_v1->lcm_entries[0]);
+               entry = comp_v1->lcm_entries;
+               for (i = 0; i < entry_count; i++, entry++) {
+                       offset = le32_to_cpu(entry->lcme_offset);
+                       lum = (struct lov_user_md_v1 *)((char *)comp_v1 +
+                                                       offset);
+                       if (le32_to_cpu(lum->lmm_magic) != LOV_USER_MAGIC_V1)
+                               /* the i-th component includes pool info */
+                               break;
+                       if (lum->lmm_pattern == cpu_to_le32(LOV_PATTERN_MDT))
+                               size += sizeof(struct lov_user_md_v1);
+                       else
+                               size += sizeof(struct lov_user_md_v3);
+               }
+
+               if (i == entry_count) {
+                       /*
+                        * re-compose the layout to include the pool for
+                        * each component
+                        */
+                       if (info->lti_ea_store_size < size)
+                               rc = lod_ea_store_resize(info, size);
+
+                       if (rc == 0) {
+                               comp_v1p = info->lti_ea_store;
+                               *comp_v1p = *comp_v1;
+                               comp_v1p->lcm_size = cpu_to_le32(size);
+                               embed_pool_to_comp_v1(comp_v1, pool, comp_v1p);
+
+                               info->lti_buf.lb_buf = comp_v1p;
+                               info->lti_buf.lb_len = size;
+                               rc = lod_xattr_set_lov_on_dir(env, dt,
+                                                             &info->lti_buf,
+                                                             name, fl, th);
+                       }
+               } else {
+                       rc = lod_xattr_set_lov_on_dir(env, dt, buf, name, fl,
+                                                     th);
+               }
+       } else {
+               rc = lod_xattr_set_lov_on_dir(env, dt, buf, name, fl, th);
+       }
+
+       if (lds->lds_def_striping_set == 1 && lds->lds_def_comp_entries != NULL)
+               lod_free_def_comp_entries(lds);
+
+       RETURN(rc);
+}
+
 /**
  * Set default striping on a directory object.
  *
@@ -3541,20 +4214,23 @@ static int lod_xattr_set_default_lmv_on_dir(const struct lu_env *env,
                                            const char *name, int fl,
                                            struct thandle *th)
 {
-       struct lmv_user_md_v1   *lum;
-       int                      rc;
+       struct lmv_user_md_v1 *lum;
+       int rc;
+
        ENTRY;
 
        LASSERT(buf != NULL && buf->lb_buf != NULL);
        lum = buf->lb_buf;
 
-       CDEBUG(D_OTHER, "set default stripe_count # %u stripe_offset %d\n",
+       CDEBUG(D_INFO,
+              "set default stripe_count # %u stripe_offset %d hash %u\n",
              le32_to_cpu(lum->lum_stripe_count),
-             (int)le32_to_cpu(lum->lum_stripe_offset));
+             (int)le32_to_cpu(lum->lum_stripe_offset),
+             le32_to_cpu(lum->lum_hash_type));
 
        if (LMVEA_DELETE_VALUES((le32_to_cpu(lum->lum_stripe_count)),
                                 le32_to_cpu(lum->lum_stripe_offset)) &&
-                               le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC) {
+           le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC) {
                rc = lod_xattr_del_internal(env, dt, name, th);
                if (rc == -ENODATA)
                        rc = 0;
@@ -3608,14 +4284,21 @@ static int lod_xattr_set_lmv(const struct lu_env *env, struct dt_object *dt,
 
        /* The stripes are supposed to be allocated in declare phase,
         * if there are no stripes being allocated, it will skip */
-       if (lo->ldo_dir_stripe_count == 0)
+       if (lo->ldo_dir_stripe_count == 0) {
+               if (lo->ldo_is_foreign) {
+                       rc = lod_sub_xattr_set(env, dt_object_child(dt), buf,
+                                              XATTR_NAME_LMV, fl, th);
+                       if (rc != 0)
+                               RETURN(rc);
+               }
                RETURN(0);
+       }
 
        rc = dt_attr_get(env, dt_object_child(dt), attr);
        if (rc != 0)
                RETURN(rc);
 
-       attr->la_valid = LA_ATIME | LA_MTIME | LA_CTIME |
+       attr->la_valid = LA_ATIME | LA_MTIME | LA_CTIME | LA_FLAGS |
                         LA_MODE | LA_UID | LA_GID | LA_TYPE | LA_PROJID;
        dof->dof_type = DFT_DIR;
 
@@ -3640,10 +4323,24 @@ static int lod_xattr_set_lmv(const struct lu_env *env, struct dt_object *dt,
                struct linkea_data ldata = { NULL };
                struct lu_buf linkea_buf;
 
-               /* if it's source stripe of migrating directory, don't create */
-               if (!((lo->ldo_dir_hash_type & LMV_HASH_FLAG_MIGRATION) &&
-                     i >= lo->ldo_dir_migrate_offset)) {
-                       dt_write_lock(env, dto, MOR_TGT_CHILD);
+               /* OBD_FAIL_MDS_STRIPE_FID may leave stripe uninitialized */
+               if (!dto)
+                       continue;
+
+               /* fail a remote stripe creation */
+               if (i && OBD_FAIL_CHECK(OBD_FAIL_MDS_STRIPE_CREATE))
+                       continue;
+
+               /* don't create stripe if:
+                * 1. it's source stripe of migrating directory
+                * 2. it's existed stripe of splitting directory
+                */
+               if ((lod_is_migrating(lo) && i >= lo->ldo_dir_migrate_offset) ||
+                   (lod_is_splitting(lo) && i < lo->ldo_dir_split_offset)) {
+                       if (!dt_object_exists(dto))
+                               GOTO(out, rc = -EINVAL);
+               } else {
+                       dt_write_lock(env, dto, DT_TGT_CHILD);
                        rc = lod_sub_create(env, dto, attr, NULL, dof, th);
                        if (rc != 0) {
                                dt_write_unlock(env, dto);
@@ -3658,17 +4355,11 @@ static int lod_xattr_set_lmv(const struct lu_env *env, struct dt_object *dt,
                        rec->rec_fid = lu_object_fid(&dto->do_lu);
                        rc = lod_sub_insert(env, dto,
                                            (const struct dt_rec *)rec,
-                                           (const struct dt_key *)dot, th, 0);
+                                           (const struct dt_key *)dot, th);
                        if (rc != 0)
                                GOTO(out, rc);
                }
 
-               rec->rec_fid = lu_object_fid(&dt->do_lu);
-               rc = lod_sub_insert(env, dto, (struct dt_rec *)rec,
-                                   (const struct dt_key *)dotdot, th, 0);
-               if (rc != 0)
-                       GOTO(out, rc);
-
                if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_SLAVE_LMV) ||
                    cfs_fail_val != i) {
                        if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_SLAVE_LMV) &&
@@ -3680,11 +4371,26 @@ static int lod_xattr_set_lmv(const struct lu_env *env, struct dt_object *dt,
                                                        cpu_to_le32(i);
 
                        rc = lod_sub_xattr_set(env, dto, &slave_lmv_buf,
-                                              XATTR_NAME_LMV, fl, th);
+                                              XATTR_NAME_LMV, 0, th);
                        if (rc != 0)
                                GOTO(out, rc);
                }
 
+               /* don't insert stripe if it's existed stripe of splitting
+                * directory (this directory is striped).
+                * NB, plain directory will insert itself as the first
+                * stripe in target.
+                */
+               if (lod_is_splitting(lo) && lo->ldo_dir_split_offset > 1 &&
+                   lo->ldo_dir_split_offset > i)
+                       continue;
+
+               rec->rec_fid = lu_object_fid(&dt->do_lu);
+               rc = lod_sub_insert(env, dto, (struct dt_rec *)rec,
+                                   (const struct dt_key *)dotdot, th);
+               if (rc != 0)
+                       GOTO(out, rc);
+
                if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_SLAVE_NAME) &&
                    cfs_fail_val == i)
                        snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
@@ -3709,7 +4415,7 @@ static int lod_xattr_set_lmv(const struct lu_env *env, struct dt_object *dt,
                rec->rec_fid = lu_object_fid(&dto->do_lu);
                rc = lod_sub_insert(env, dt_object_child(dt),
                                    (const struct dt_rec *)rec,
-                                   (const struct dt_key *)stripe_name, th, 0);
+                                   (const struct dt_key *)stripe_name, th);
                if (rc != 0)
                        GOTO(out, rc);
 
@@ -3801,12 +4507,36 @@ static int lod_dir_striping_create_internal(const struct lu_env *env,
                                               th);
                if (rc != 0)
                        RETURN(rc);
+       } else {
+               /* foreign LMV EA case */
+               if (lmu) {
+                       struct lmv_foreign_md *lfm = lmu->lb_buf;
+
+                       if (lfm->lfm_magic == LMV_MAGIC_FOREIGN) {
+                               rc = lod_declare_xattr_set_lmv(env, dt, attr,
+                                                              lmu, dof, th);
+                       }
+               } else {
+                       if (lo->ldo_is_foreign) {
+                               LASSERT(lo->ldo_foreign_lmv != NULL &&
+                                       lo->ldo_foreign_lmv_size > 0);
+                               info->lti_buf.lb_buf = lo->ldo_foreign_lmv;
+                               info->lti_buf.lb_len = lo->ldo_foreign_lmv_size;
+                               lmu = &info->lti_buf;
+                               rc = lod_xattr_set_lmv(env, dt, lmu,
+                                                      XATTR_NAME_LMV, 0, th);
+                       }
+               }
        }
 
        /* Transfer default LMV striping from the parent */
        if (lds != NULL && lds->lds_dir_def_striping_set &&
-           !LMVEA_DELETE_VALUES(lds->lds_dir_def_stripe_count,
-                                lds->lds_dir_def_stripe_offset)) {
+           lds->lds_dir_def_max_inherit != LMV_INHERIT_END &&
+           lds->lds_dir_def_max_inherit != LMV_INHERIT_NONE &&
+           !(LMVEA_DELETE_VALUES(lds->lds_dir_def_stripe_count,
+                                lds->lds_dir_def_stripe_offset) &&
+             le32_to_cpu(lds->lds_dir_def_hash_type) !=
+             LMV_HASH_TYPE_UNKNOWN)) {
                struct lmv_user_md_v1 *v1 = info->lti_ea_store;
 
                if (info->lti_ea_store_size < sizeof(*v1)) {
@@ -3824,6 +4554,10 @@ static int lod_dir_striping_create_internal(const struct lu_env *env,
                        cpu_to_le32(lds->lds_dir_def_stripe_offset);
                v1->lum_hash_type =
                        cpu_to_le32(lds->lds_dir_def_hash_type);
+               v1->lum_max_inherit =
+                       lmv_inherit_next(lds->lds_dir_def_max_inherit);
+               v1->lum_max_inherit_rr =
+                       lmv_inherit_rr_next(lds->lds_dir_def_max_inherit_rr);
 
                info->lti_buf.lb_buf = v1;
                info->lti_buf.lb_len = sizeof(*v1);
@@ -3870,6 +4604,12 @@ static int lod_dir_striping_create_internal(const struct lu_env *env,
                        RETURN(rc);
        }
 
+       /* ldo_def_striping is not allocated, clear after use, in case directory
+        * layout is changed later.
+        */
+       if (!declare)
+               lo->ldo_def_striping = NULL;
+
        RETURN(0);
 }
 
@@ -3922,8 +4662,8 @@ static int lod_generate_and_set_lovea(const struct lu_env *env,
 
        LASSERT(lo);
 
-       if (lo->ldo_comp_cnt == 0) {
-               lod_striping_free(env, lo);
+       if (lo->ldo_comp_cnt == 0 && !lo->ldo_is_foreign) {
+               lod_striping_free_nolock(env, lo);
                rc = lod_sub_xattr_del(env, next, XATTR_NAME_LOV, th);
                RETURN(rc);
        }
@@ -3947,37 +4687,194 @@ static int lod_generate_and_set_lovea(const struct lu_env *env,
        RETURN(rc);
 }
 
+static __u32 lod_gen_component_id(struct lod_object *lo,
+                                 int mirror_id, int comp_idx);
+
 /**
- * Delete layout component(s)
+ * Repeat an existing component
+ *
+ * Creates a new layout by replicating an existing component.  Uses striping
+ * policy from previous component as a template for the striping for the new
+ * new component.
+ *
+ * New component starts with zero length, will be extended (or removed) before
+ * returning layout to client.
+ *
+ * NB: Reallocates layout components array (lo->ldo_comp_entries), invalidating
+ * any pre-existing pointers to components.  Handle with care.
  *
  * \param[in] env      execution environment for this thread
- * \param[in] dt       object
- * \param[in] th       transaction handle
+ * \param[in,out] lo   object to update the layout of
+ * \param[in] index    index of component to copy
  *
  * \retval     0 on success
- * \retval     negative error number on failure
+ * \retval     negative errno on error
  */
-static int lod_layout_del(const struct lu_env *env, struct dt_object *dt,
-                         struct thandle *th)
+static int lod_layout_repeat_comp(const struct lu_env *env,
+                                 struct lod_object *lo, int index)
 {
-       struct lod_layout_component     *lod_comp;
-       struct lod_object       *lo = lod_dt_obj(dt);
-       struct dt_object        *next = dt_object_child(dt);
-       struct lu_attr  *attr = &lod_env_info(env)->lti_attr;
-       int     rc, i, j, left;
+       struct lod_layout_component *lod_comp;
+       struct lod_layout_component *new_comp = NULL;
+       struct lod_layout_component *comp_array;
+       int rc = 0, i, new_cnt = lo->ldo_comp_cnt + 1;
+       __u16 mirror_id;
+       int offset = 0;
+       ENTRY;
+
+       lod_comp = &lo->ldo_comp_entries[index];
+       LASSERT(lod_comp_inited(lod_comp) && lod_comp->llc_id != LCME_ID_INVAL);
+
+       CDEBUG(D_LAYOUT, "repeating component %d\n", index);
+
+       OBD_ALLOC_PTR_ARRAY(comp_array, new_cnt);
+       if (comp_array == NULL)
+               GOTO(out, rc = -ENOMEM);
+
+       for (i = 0; i < lo->ldo_comp_cnt; i++) {
+               memcpy(&comp_array[i + offset], &lo->ldo_comp_entries[i],
+                      sizeof(*comp_array));
+
+               /* Duplicate this component in to the next slot */
+               if (i == index) {
+                       new_comp = &comp_array[i + 1];
+                       memcpy(&comp_array[i + 1], &lo->ldo_comp_entries[i],
+                              sizeof(*comp_array));
+                       /* We must now skip this new component when copying */
+                       offset = 1;
+               }
+       }
+
+       /* Set up copied component */
+       new_comp->llc_flags &= ~LCME_FL_INIT;
+       new_comp->llc_stripe = NULL;
+       new_comp->llc_stripes_allocated = 0;
+       new_comp->llc_ost_indices = NULL;
+       new_comp->llc_stripe_offset = LOV_OFFSET_DEFAULT;
+       /* for uninstantiated components, layout gen stores default stripe
+        * offset */
+       new_comp->llc_layout_gen = lod_comp->llc_stripe_offset;
+       /* This makes the repeated component zero-length, placed at the end of
+        * the preceding component */
+       new_comp->llc_extent.e_start = new_comp->llc_extent.e_end;
+       new_comp->llc_timestamp = lod_comp->llc_timestamp;
+       new_comp->llc_pool = NULL;
+
+       rc = lod_set_pool(&new_comp->llc_pool, lod_comp->llc_pool);
+       if (rc)
+               GOTO(out, rc);
+
+       if (new_comp->llc_ostlist.op_array) {
+               __u32 *op_array = NULL;
+
+               OBD_ALLOC(op_array, new_comp->llc_ostlist.op_size);
+               if (!op_array)
+                       GOTO(out, rc = -ENOMEM);
+               memcpy(op_array, &new_comp->llc_ostlist.op_array,
+                      new_comp->llc_ostlist.op_size);
+               new_comp->llc_ostlist.op_array = op_array;
+       }
+
+       OBD_FREE_PTR_ARRAY(lo->ldo_comp_entries, lo->ldo_comp_cnt);
+       lo->ldo_comp_entries = comp_array;
+       lo->ldo_comp_cnt = new_cnt;
+
+       /* Generate an id for the new component */
+       mirror_id = mirror_id_of(new_comp->llc_id);
+       new_comp->llc_id = LCME_ID_INVAL;
+       new_comp->llc_id = lod_gen_component_id(lo, mirror_id, index + 1);
+       if (new_comp->llc_id == LCME_ID_INVAL)
+               GOTO(out, rc = -ERANGE);
+
+       EXIT;
+out:
+       if (rc)
+               OBD_FREE_PTR_ARRAY(comp_array, new_cnt);
+
+       return rc;
+}
+
+static int lod_layout_data_init(struct lod_thread_info *info, __u32 comp_cnt)
+{
+       ENTRY;
+
+       /* clear memory region that will be used for layout change */
+       memset(&info->lti_layout_attr, 0, sizeof(struct lu_attr));
+       info->lti_count = 0;
+
+       if (info->lti_comp_size >= comp_cnt)
+               RETURN(0);
+
+       if (info->lti_comp_size > 0) {
+               OBD_FREE_PTR_ARRAY(info->lti_comp_idx, info->lti_comp_size);
+               info->lti_comp_size = 0;
+       }
+
+       OBD_ALLOC_PTR_ARRAY(info->lti_comp_idx, comp_cnt);
+       if (!info->lti_comp_idx)
+               RETURN(-ENOMEM);
+
+       info->lti_comp_size = comp_cnt;
+       RETURN(0);
+}
+
+/**
+ * Prepare new layout minus deleted components
+ *
+ * Removes components marked for deletion (LCME_ID_INVAL) by copying to a new
+ * layout and skipping those components.  Removes stripe objects if any exist.
+ *
+ * NB:
+ * Reallocates layout components array (lo->ldo_comp_entries), invalidating
+ * any pre-existing pointers to components.
+ *
+ * Caller is responsible for updating mirror end (ldo_mirror[].lme_end).
+ *
+ * \param[in] env       execution environment for this thread
+ * \param[in,out] lo    object to update the layout of
+ * \param[in] th        transaction handle for this operation
+ *
+ * \retval      # of components deleted
+ * \retval      negative errno on error
+ */
+static int lod_layout_del_prep_layout(const struct lu_env *env,
+                                     struct lod_object *lo,
+                                     struct thandle *th)
+{
+       struct lod_layout_component     *lod_comp;
+       struct lod_thread_info  *info = lod_env_info(env);
+       int rc = 0, i, j, deleted = 0;
+
+       ENTRY;
 
        LASSERT(lo->ldo_is_composite);
        LASSERT(lo->ldo_comp_cnt > 0 && lo->ldo_comp_entries != NULL);
 
-       left = lo->ldo_comp_cnt;
-       for (i = (lo->ldo_comp_cnt - 1); i >= 0; i--) {
+       rc = lod_layout_data_init(info, lo->ldo_comp_cnt);
+       if (rc)
+               RETURN(rc);
+
+       for (i = 0; i < lo->ldo_comp_cnt; i++) {
                lod_comp = &lo->ldo_comp_entries[i];
 
-               if (lod_comp->llc_id != LCME_ID_INVAL)
-                       break;
-               left--;
+               if (lod_comp->llc_id != LCME_ID_INVAL) {
+                       /* Build array of things to keep */
+                       info->lti_comp_idx[info->lti_count++] = i;
+                       continue;
+               }
 
-               /* Not instantiated component */
+               lod_obj_set_pool(lo, i, NULL);
+               if (lod_comp->llc_ostlist.op_array) {
+                       OBD_FREE(lod_comp->llc_ostlist.op_array,
+                                lod_comp->llc_ostlist.op_size);
+                       lod_comp->llc_ostlist.op_array = NULL;
+                       lod_comp->llc_ostlist.op_size = 0;
+               }
+
+               deleted++;
+               CDEBUG(D_LAYOUT, "deleting comp %d, left %d\n", i,
+                      lo->ldo_comp_cnt - deleted);
+
+               /* No striping info for this component */
                if (lod_comp->llc_stripe == NULL)
                        continue;
 
@@ -3987,52 +4884,93 @@ static int lod_layout_del(const struct lu_env *env, struct dt_object *dt,
 
                        if (obj == NULL)
                                continue;
-                       rc = lod_sub_destroy(env, obj, th);
-                       if (rc)
-                               GOTO(out, rc);
+
+                       /* components which are not init have no sub objects
+                        * to destroy */
+                       if (lod_comp_inited(lod_comp)) {
+                               rc = lod_sub_destroy(env, obj, th);
+                               if (rc)
+                                       GOTO(out, rc);
+                       }
 
                        lu_object_put(env, &obj->do_lu);
                        lod_comp->llc_stripe[j] = NULL;
                }
-               OBD_FREE(lod_comp->llc_stripe, sizeof(struct dt_object *) *
-                                       lod_comp->llc_stripes_allocated);
+               OBD_FREE_PTR_ARRAY(lod_comp->llc_stripe,
+                                  lod_comp->llc_stripes_allocated);
                lod_comp->llc_stripe = NULL;
-               OBD_FREE(lod_comp->llc_ost_indices,
-                        sizeof(__u32) * lod_comp->llc_stripes_allocated);
+               OBD_FREE_PTR_ARRAY(lod_comp->llc_ost_indices,
+                                  lod_comp->llc_stripes_allocated);
                lod_comp->llc_ost_indices = NULL;
                lod_comp->llc_stripes_allocated = 0;
-               lod_obj_set_pool(lo, i, NULL);
-               if (lod_comp->llc_ostlist.op_array) {
-                       OBD_FREE(lod_comp->llc_ostlist.op_array,
-                                lod_comp->llc_ostlist.op_size);
-                       lod_comp->llc_ostlist.op_array = NULL;
-                       lod_comp->llc_ostlist.op_size = 0;
-               }
        }
 
-       LASSERTF(left >= 0 && left < lo->ldo_comp_cnt, "left = %d\n", left);
-       if (left > 0) {
-               struct lod_layout_component     *comp_array;
+       /* info->lti_count has the amount of left components */
+       LASSERTF(info->lti_count >= 0 && info->lti_count < lo->ldo_comp_cnt,
+                "left = %d, lo->ldo_comp_cnt %d\n", (int)info->lti_count,
+                (int)lo->ldo_comp_cnt);
+
+       if (info->lti_count > 0) {
+               struct lod_layout_component *comp_array;
 
-               OBD_ALLOC(comp_array, sizeof(*comp_array) * left);
+               OBD_ALLOC_PTR_ARRAY(comp_array, info->lti_count);
                if (comp_array == NULL)
                        GOTO(out, rc = -ENOMEM);
 
-               memcpy(&comp_array[0], &lo->ldo_comp_entries[0],
-                      sizeof(*comp_array) * left);
+               for (i = 0; i < info->lti_count; i++) {
+                       memcpy(&comp_array[i],
+                              &lo->ldo_comp_entries[info->lti_comp_idx[i]],
+                              sizeof(*comp_array));
+               }
 
-               OBD_FREE(lo->ldo_comp_entries,
-                        sizeof(*comp_array) * lo->ldo_comp_cnt);
+               OBD_FREE_PTR_ARRAY(lo->ldo_comp_entries, lo->ldo_comp_cnt);
                lo->ldo_comp_entries = comp_array;
-               lo->ldo_comp_cnt = left;
-
-               LASSERT(lo->ldo_mirror_count == 1);
-               lo->ldo_mirrors[0].lme_end = left - 1;
-               lod_obj_inc_layout_gen(lo);
+               lo->ldo_comp_cnt = info->lti_count;
        } else {
                lod_free_comp_entries(lo);
        }
 
+       EXIT;
+out:
+       return rc ? rc : deleted;
+}
+
+/**
+ * Delete layout component(s)
+ *
+ * This function sets up the layout data in the env and does the setattrs
+ * required to write out the new layout.  The layout itself is modified in
+ * lod_layout_del_prep_layout.
+ *
+ * \param[in] env      execution environment for this thread
+ * \param[in] dt       object
+ * \param[in] th       transaction handle
+ *
+ * \retval     0 on success
+ * \retval     negative error number on failure
+ */
+static int lod_layout_del(const struct lu_env *env, struct dt_object *dt,
+                         struct thandle *th)
+{
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next = dt_object_child(dt);
+       struct lu_attr *attr = &lod_env_info(env)->lti_attr;
+       int rc;
+
+       LASSERT(lo->ldo_mirror_count == 1);
+
+       mutex_lock(&lo->ldo_layout_mutex);
+
+       rc = lod_layout_del_prep_layout(env, lo, th);
+       if (rc < 0)
+               GOTO(out, rc);
+
+       /* Only do this if we didn't delete all components */
+       if (lo->ldo_comp_cnt > 0) {
+               lo->ldo_mirrors[0].lme_end = lo->ldo_comp_cnt - 1;
+               lod_obj_inc_layout_gen(lo);
+       }
+
        LASSERT(dt_object_exists(dt));
        rc = dt_attr_get(env, next, attr);
        if (rc)
@@ -4050,14 +4988,14 @@ static int lod_layout_del(const struct lu_env *env, struct dt_object *dt,
        EXIT;
 out:
        if (rc)
-               lod_striping_free(env, lo);
+               lod_striping_free_nolock(env, lo);
+
+       mutex_unlock(&lo->ldo_layout_mutex);
+
        return rc;
 }
 
 
-static int lod_get_default_lov_striping(const struct lu_env *env,
-                                       struct lod_object *lo,
-                                       struct lod_default_striping *lds);
 /**
  * Implementation of dt_object_operations::do_xattr_set.
  *
@@ -4080,83 +5018,33 @@ static int lod_xattr_set(const struct lu_env *env,
                         struct dt_object *dt, const struct lu_buf *buf,
                         const char *name, int fl, struct thandle *th)
 {
-       struct dt_object        *next = dt_object_child(dt);
-       int                      rc;
+       struct dt_object *next = dt_object_child(dt);
+       struct lu_attr *layout_attr = &lod_env_info(env)->lti_layout_attr;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lod_obj_stripe_cb_data data = { {0} };
+       int rc = 0;
+
        ENTRY;
 
        if (S_ISDIR(dt->do_lu.lo_header->loh_attr) &&
-           strcmp(name, XATTR_NAME_LMV) == 0) {
-               rc = lod_dir_striping_create(env, dt, NULL, NULL, th);
-               RETURN(rc);
-       } else if (S_ISDIR(dt->do_lu.lo_header->loh_attr) &&
-                  strncmp(name, XATTR_NAME_LMV, strlen(XATTR_NAME_LMV)) == 0 &&
-                  strlen(name) > strlen(XATTR_NAME_LMV) + 1) {
-               const char *op = name + strlen(XATTR_NAME_LMV) + 1;
-
-               rc = -ENOTSUPP;
-               if (strcmp(op, "del") == 0)
-                       rc = lod_dir_layout_delete(env, dt, buf, th);
-               /*
-                * XATTR_NAME_LMV".add" is never called, but only declared,
-                * because lod_xattr_set_lmv() will do the addition.
-                */
+           !strcmp(name, XATTR_NAME_LMV)) {
+               switch (fl) {
+               case LU_XATTR_CREATE:
+                       rc = lod_dir_striping_create(env, dt, NULL, NULL, th);
+                       break;
+               case 0:
+               case LU_XATTR_REPLACE:
+                       rc = lod_dir_layout_set(env, dt, buf, fl, th);
+                       break;
+               default:
+                       LBUG();
+               }
 
                RETURN(rc);
        } else if (S_ISDIR(dt->do_lu.lo_header->loh_attr) &&
-           strcmp(name, XATTR_NAME_LOV) == 0) {
-               struct lod_thread_info *info = lod_env_info(env);
-               struct lod_default_striping *lds = &info->lti_def_striping;
-               struct lov_user_md_v1 *v1 = buf->lb_buf;
-               char pool[LOV_MAXPOOLNAME + 1];
-               bool is_del;
-
-               /* get existing striping config */
-               rc = lod_get_default_lov_striping(env, lod_dt_obj(dt), lds);
-               if (rc)
-                       RETURN(rc);
-
-               memset(pool, 0, sizeof(pool));
-               if (lds->lds_def_striping_set == 1)
-                       lod_layout_get_pool(lds->lds_def_comp_entries,
-                                           lds->lds_def_comp_cnt, pool,
-                                           sizeof(pool));
-
-               is_del = LOVEA_DELETE_VALUES(v1->lmm_stripe_size,
-                                            v1->lmm_stripe_count,
-                                            v1->lmm_stripe_offset,
-                                            NULL);
-
-               /* Retain the pool name if it is not given */
-               if (v1->lmm_magic == LOV_USER_MAGIC_V1 && pool[0] != '\0' &&
-                       !is_del) {
-                       struct lod_thread_info *info = lod_env_info(env);
-                       struct lov_user_md_v3 *v3  = info->lti_ea_store;
-
-                       memset(v3, 0, sizeof(*v3));
-                       v3->lmm_magic = cpu_to_le32(LOV_USER_MAGIC_V3);
-                       v3->lmm_pattern = cpu_to_le32(v1->lmm_pattern);
-                       v3->lmm_stripe_count =
-                                       cpu_to_le32(v1->lmm_stripe_count);
-                       v3->lmm_stripe_offset =
-                                       cpu_to_le32(v1->lmm_stripe_offset);
-                       v3->lmm_stripe_size = cpu_to_le32(v1->lmm_stripe_size);
-
-                       strlcpy(v3->lmm_pool_name, pool,
-                               sizeof(v3->lmm_pool_name));
-
-                       info->lti_buf.lb_buf = v3;
-                       info->lti_buf.lb_len = sizeof(*v3);
-                       rc = lod_xattr_set_lov_on_dir(env, dt, &info->lti_buf,
-                                                     name, fl, th);
-               } else {
-                       rc = lod_xattr_set_lov_on_dir(env, dt, buf, name,
-                                                     fl, th);
-               }
-
-               if (lds->lds_def_striping_set == 1 &&
-                   lds->lds_def_comp_entries != NULL)
-                       lod_free_def_comp_entries(lds);
-
+                  strcmp(name, XATTR_NAME_LOV) == 0) {
+               rc = lod_xattr_set_default_lov_on_dir(env, dt, buf, name, fl,
+                                                     th);
                RETURN(rc);
        } else if (S_ISDIR(dt->do_lu.lo_header->loh_attr) &&
                   strcmp(name, XATTR_NAME_DEFAULT_LMV) == 0) {
@@ -4165,9 +5053,9 @@ static int lod_xattr_set(const struct lu_env *env,
                                                      th);
                RETURN(rc);
        } else if (S_ISREG(dt->do_lu.lo_header->loh_attr) &&
-                  (!strcmp(name, XATTR_NAME_LOV) ||
-                   !strncmp(name, XATTR_LUSTRE_LOV,
-                            strlen(XATTR_LUSTRE_LOV)))) {
+                  (strcmp(name, XATTR_NAME_LOV) == 0 ||
+                   strcmp(name, XATTR_LUSTRE_LOV) == 0 ||
+                   allowed_lustre_lov(name))) {
                /* in case of lov EA swap, just set it
                 * if not, it is a replay so check striping match what we
                 * already have during req replay, declare_xattr_set()
@@ -4177,6 +5065,31 @@ static int lod_xattr_set(const struct lu_env *env,
                        lod_striping_free(env, lod_dt_obj(dt));
 
                        rc = lod_sub_xattr_set(env, next, buf, name, fl, th);
+               } else if (fl & LU_XATTR_SPLIT) {
+                       rc = lod_sub_xattr_set(env, next, buf, name, fl, th);
+                       if (rc)
+                               RETURN(rc);
+
+                       rc = lod_striping_reload(env, lo, buf, LVF_ALL_STALE);
+                       if (rc)
+                               RETURN(rc);
+
+                       if (lo->ldo_mirror_count > 1 &&
+                           layout_attr->la_valid & LA_LAYOUT_VERSION) {
+                               /* mirror split */
+                               layout_attr->la_layout_version =
+                                               lo->ldo_layout_gen;
+                               data.locd_attr = layout_attr;
+                               data.locd_declare = false;
+                               data.locd_stripe_cb =
+                                               lod_obj_stripe_attr_set_cb;
+                               rc = lod_obj_for_each_stripe(env, lo, th,
+                                                            &data);
+                               if (rc)
+                                       RETURN(rc);
+                       }
+               } else if (fl & LU_XATTR_PURGE) {
+                       rc = lod_layout_purge(env, dt, buf, th);
                } else if (dt_object_remote(dt)) {
                        /* This only happens during migration, see
                         * mdd_migrate_create(), in which Master MDT will
@@ -4205,10 +5118,27 @@ static int lod_xattr_set(const struct lu_env *env,
                                !lod_dt_obj(dt)->ldo_comp_cached));
 
                        rc = lod_striped_create(env, dt, NULL, NULL, th);
+                       if (rc)
+                               RETURN(rc);
+
+                       if (fl & LU_XATTR_MERGE && lo->ldo_mirror_count > 1 &&
+                           layout_attr->la_valid & LA_LAYOUT_VERSION) {
+                               /* mirror merge exec phase */
+                               layout_attr->la_layout_version =
+                                               lo->ldo_layout_gen;
+                               data.locd_attr = layout_attr;
+                               data.locd_declare = false;
+                               data.locd_stripe_cb =
+                                               lod_obj_stripe_attr_set_cb;
+                               rc = lod_obj_for_each_stripe(env, lo, th,
+                                                            &data);
+                               if (rc)
+                                       RETURN(rc);
+                       }
                }
                RETURN(rc);
        } else if (strcmp(name, XATTR_NAME_FID) == 0) {
-               rc = lod_replace_parent_fid(env, dt, th, false);
+               rc = lod_replace_parent_fid(env, dt, buf, th, false);
 
                RETURN(rc);
        }
@@ -4242,7 +5172,13 @@ static int lod_declare_xattr_del(const struct lu_env *env,
        if (!S_ISDIR(dt->do_lu.lo_header->loh_attr))
                RETURN(0);
 
-       /* set xattr to each stripes, if needed */
+       /* NB: don't delete stripe LMV, because when we do this, normally we
+        * will remove stripes, besides, if directory LMV is corrupt, this will
+        * prevent deleting its LMV and fixing it (via LFSCK).
+        */
+       if (!strcmp(name, XATTR_NAME_LMV))
+               RETURN(0);
+
        rc = lod_striping_load(env, lo);
        if (rc != 0)
                RETURN(rc);
@@ -4253,7 +5189,12 @@ static int lod_declare_xattr_del(const struct lu_env *env,
        for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
                struct dt_object *dto = lo->ldo_stripe[i];
 
-               LASSERT(dto);
+               if (!dto)
+                       continue;
+
+               if (!dt_object_exists(dto))
+                       continue;
+
                rc = lod_sub_declare_xattr_del(env, dto, name, th);
                if (rc != 0)
                        break;
@@ -4273,31 +5214,14 @@ static int lod_declare_xattr_del(const struct lu_env *env,
 static int lod_xattr_del(const struct lu_env *env, struct dt_object *dt,
                         const char *name, struct thandle *th)
 {
-       struct dt_object        *next = dt_object_child(dt);
-       struct lod_object       *lo = lod_dt_obj(dt);
-       int                     rc;
-       int                     i;
+       int rc;
+
        ENTRY;
 
        if (!strcmp(name, XATTR_NAME_LOV) || !strcmp(name, XATTR_NAME_LMV))
                lod_striping_free(env, lod_dt_obj(dt));
 
-       rc = lod_sub_xattr_del(env, next, name, th);
-       if (rc != 0 || !S_ISDIR(dt->do_lu.lo_header->loh_attr))
-               RETURN(rc);
-
-       if (lo->ldo_dir_stripe_count == 0)
-               RETURN(0);
-
-       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-               struct dt_object *dto = lo->ldo_stripe[i];
-
-               LASSERT(dto);
-
-               rc = lod_sub_xattr_del(env, dto, name, th);
-               if (rc != 0)
-                       break;
-       }
+       rc = lod_xattr_del_internal(env, dt, name, th);
 
        RETURN(rc);
 }
@@ -4378,16 +5302,24 @@ skip:
  */
 static int lod_get_default_lov_striping(const struct lu_env *env,
                                        struct lod_object *lo,
-                                       struct lod_default_striping *lds)
+                                       struct lod_default_striping *lds,
+                                       struct dt_allocation_hint *dah)
 {
        struct lod_thread_info *info = lod_env_info(env);
        struct lov_user_md_v1 *v1 = NULL;
        struct lov_user_md_v3 *v3 = NULL;
-       struct lov_comp_md_v1 *comp_v1 = NULL;
-       __u16   comp_cnt;
-       __u16   mirror_cnt;
-       bool    composite;
-       int     rc, i, j;
+       struct lov_comp_md_v1 *lcm = NULL;
+       __u32 magic;
+       int append_stripe_count = dah != NULL ? dah->dah_append_stripe_count : 0;
+       const char *append_pool = (dah != NULL &&
+                                  dah->dah_append_pool != NULL &&
+                                  dah->dah_append_pool[0] != '\0') ?
+                                 dah->dah_append_pool : NULL;
+       __u16 entry_count = 1;
+       __u16 mirror_count = 0;
+       bool want_composite = false;
+       int rc, i, j;
+
        ENTRY;
 
        lds->lds_def_striping_set = 0;
@@ -4399,105 +5331,133 @@ static int lod_get_default_lov_striping(const struct lu_env *env,
        if (rc < (typeof(rc))sizeof(struct lov_user_md))
                RETURN(0);
 
-       v1 = info->lti_ea_store;
-       if (v1->lmm_magic == __swab32(LOV_USER_MAGIC_V1)) {
-               lustre_swab_lov_user_md_v1(v1);
-       } else if (v1->lmm_magic == __swab32(LOV_USER_MAGIC_V3)) {
-               v3 = (struct lov_user_md_v3 *)v1;
-               lustre_swab_lov_user_md_v3(v3);
-       } else if (v1->lmm_magic == __swab32(LOV_USER_MAGIC_SPECIFIC)) {
-               v3 = (struct lov_user_md_v3 *)v1;
+       magic = *(__u32 *)info->lti_ea_store;
+       if (magic == __swab32(LOV_USER_MAGIC_V1)) {
+               lustre_swab_lov_user_md_v1(info->lti_ea_store);
+       } else if (magic == __swab32(LOV_USER_MAGIC_V3)) {
+               lustre_swab_lov_user_md_v3(info->lti_ea_store);
+       } else if (magic == __swab32(LOV_USER_MAGIC_SPECIFIC)) {
+               v3 = (struct lov_user_md_v3 *)info->lti_ea_store;
                lustre_swab_lov_user_md_v3(v3);
                lustre_swab_lov_user_md_objects(v3->lmm_objects,
                                                v3->lmm_stripe_count);
-       } else if (v1->lmm_magic == __swab32(LOV_USER_MAGIC_COMP_V1)) {
-               comp_v1 = (struct lov_comp_md_v1 *)v1;
-               lustre_swab_lov_comp_md_v1(comp_v1);
+       } else if (magic == __swab32(LOV_USER_MAGIC_COMP_V1) ||
+                  magic == __swab32(LOV_USER_MAGIC_SEL)) {
+               lustre_swab_lov_comp_md_v1(info->lti_ea_store);
        }
 
-       if (v1->lmm_magic != LOV_MAGIC_V3 && v1->lmm_magic != LOV_MAGIC_V1 &&
-           v1->lmm_magic != LOV_MAGIC_COMP_V1 &&
-           v1->lmm_magic != LOV_USER_MAGIC_SPECIFIC)
+       switch (magic) {
+       case LOV_MAGIC_V1:
+       case LOV_MAGIC_V3:
+       case LOV_USER_MAGIC_SPECIFIC:
+               v1 = info->lti_ea_store;
+               break;
+       case LOV_MAGIC_COMP_V1:
+       case LOV_MAGIC_SEL:
+               lcm = info->lti_ea_store;
+               entry_count = lcm->lcm_entry_count;
+               if (entry_count == 0)
+                       RETURN(-EINVAL);
+
+               mirror_count = lcm->lcm_mirror_count + 1;
+               want_composite = true;
+               break;
+       default:
                RETURN(-ENOTSUPP);
+       }
 
-       if (v1->lmm_magic == LOV_MAGIC_COMP_V1) {
-               comp_v1 = (struct lov_comp_md_v1 *)v1;
-               comp_cnt = comp_v1->lcm_entry_count;
-               if (comp_cnt == 0)
-                       RETURN(-EINVAL);
-               mirror_cnt = comp_v1->lcm_mirror_count + 1;
-               composite = true;
-       } else {
-               comp_cnt = 1;
-               mirror_cnt = 0;
-               composite = false;
+       if (append_stripe_count != 0 || append_pool != NULL) {
+               entry_count = 1;
+               mirror_count = 0;
+               want_composite = false;
        }
 
        /* realloc default comp entries if necessary */
-       rc = lod_def_striping_comp_resize(lds, comp_cnt);
+       rc = lod_def_striping_comp_resize(lds, entry_count);
        if (rc < 0)
                RETURN(rc);
 
-       lds->lds_def_comp_cnt = comp_cnt;
-       lds->lds_def_striping_is_composite = composite;
-       lds->lds_def_mirror_cnt = mirror_cnt;
+       lds->lds_def_comp_cnt = entry_count;
+       lds->lds_def_striping_is_composite = want_composite;
+       lds->lds_def_mirror_cnt = mirror_count;
 
-       for (i = 0; i < comp_cnt; i++) {
-               struct lod_layout_component *lod_comp;
-               struct lu_extent *ext;
-               char *pool;
+       for (i = 0; i < entry_count; i++) {
+               struct lod_layout_component *llc = &lds->lds_def_comp_entries[i];
+               const char *pool;
 
-               lod_comp = &lds->lds_def_comp_entries[i];
                /*
-                * reset lod_comp values, llc_stripes is always NULL in
-                * the default striping template, llc_pool will be reset
-                * later below.
+                * reset llc values, llc_stripes is always NULL in the
+                * default striping template, llc_pool will be reset
+                * later below using lod_set_pool().
+                *
+                * XXX At this point llc_pool may point to valid (!)
+                * kmalloced strings from previous RPCs.
                 */
-               memset(lod_comp, 0, offsetof(typeof(*lod_comp), llc_pool));
+               memset(llc, 0, offsetof(typeof(*llc), llc_pool));
 
-               if (composite) {
-                       v1 = (struct lov_user_md *)((char *)comp_v1 +
-                                       comp_v1->lcm_entries[i].lcme_offset);
-                       ext = &comp_v1->lcm_entries[i].lcme_extent;
-                       lod_comp->llc_extent = *ext;
+               if (lcm != NULL) {
+                       v1 = (struct lov_user_md *)((char *)lcm +
+                                                   lcm->lcm_entries[i].lcme_offset);
+
+                       if (want_composite) {
+                               llc->llc_extent = lcm->lcm_entries[i].lcme_extent;
+                               /* We only inherit certain flags from the layout */
+                               llc->llc_flags = lcm->lcm_entries[i].lcme_flags &
+                                       LCME_TEMPLATE_FLAGS;
+                       }
                }
 
-               if (v1->lmm_pattern != LOV_PATTERN_RAID0 &&
-                   v1->lmm_pattern != LOV_PATTERN_MDT &&
-                   v1->lmm_pattern != 0) {
+               CDEBUG(D_LAYOUT, DFID" magic = %#08x, pattern = %#x, stripe_count = %hu, stripe_size = %u, stripe_offset = %hu, append_pool = '%s', append_stripe_count = %d\n",
+                      PFID(lu_object_fid(&lo->ldo_obj.do_lu)),
+                      v1->lmm_magic,
+                      v1->lmm_pattern,
+                      v1->lmm_stripe_count,
+                      v1->lmm_stripe_size,
+                      v1->lmm_stripe_offset,
+                      append_pool ?: "",
+                      append_stripe_count);
+
+               if (!lov_pattern_supported(v1->lmm_pattern) &&
+                   !(v1->lmm_pattern & LOV_PATTERN_F_RELEASED)) {
                        lod_free_def_comp_entries(lds);
                        RETURN(-EINVAL);
                }
 
-               CDEBUG(D_LAYOUT, DFID" stripe_count=%d stripe_size=%d "
-                      "stripe_offset=%d\n",
-                      PFID(lu_object_fid(&lo->ldo_obj.do_lu)),
-                      (int)v1->lmm_stripe_count, (int)v1->lmm_stripe_size,
-                      (int)v1->lmm_stripe_offset);
+               llc->llc_stripe_count = v1->lmm_stripe_count;
+               llc->llc_stripe_size = v1->lmm_stripe_size;
+               llc->llc_stripe_offset = v1->lmm_stripe_offset;
+               llc->llc_pattern = v1->lmm_pattern;
 
-               lod_comp->llc_stripe_count = v1->lmm_stripe_count;
-               lod_comp->llc_stripe_size = v1->lmm_stripe_size;
-               lod_comp->llc_stripe_offset = v1->lmm_stripe_offset;
-               lod_comp->llc_pattern = v1->lmm_pattern;
+               if (append_stripe_count != 0 || append_pool != NULL)
+                       llc->llc_pattern = LOV_PATTERN_RAID0;
+
+               if (append_stripe_count != 0)
+                       llc->llc_stripe_count = append_stripe_count;
 
                pool = NULL;
-               if (v1->lmm_magic == LOV_USER_MAGIC_V3) {
+               if (append_pool != NULL) {
+                       pool = append_pool;
+               } else if (v1->lmm_magic == LOV_USER_MAGIC_V3) {
                        /* XXX: sanity check here */
-                       v3 = (struct lov_user_md_v3 *) v1;
+                       v3 = (struct lov_user_md_v3 *)v1;
                        if (v3->lmm_pool_name[0] != '\0')
                                pool = v3->lmm_pool_name;
                }
-               lod_set_def_pool(lds, i, pool);
-               if (v1->lmm_magic == LOV_USER_MAGIC_SPECIFIC) {
+
+               lod_set_pool(&llc->llc_pool, pool);
+
+               if (append_stripe_count != 0 || append_pool != NULL) {
+                       /* Ignore specific striping for append. */
+               } else if (v1->lmm_magic == LOV_USER_MAGIC_SPECIFIC) {
                        v3 = (struct lov_user_md_v3 *)v1;
-                       rc = lod_comp_copy_ost_lists(lod_comp, v3);
+                       rc = lod_comp_copy_ost_lists(llc, v3);
                        if (rc)
                                RETURN(rc);
-               } else if (lod_comp->llc_ostlist.op_array &&
-                          lod_comp->llc_ostlist.op_count) {
-                       for (j = 0; j < lod_comp->llc_ostlist.op_count; j++)
-                               lod_comp->llc_ostlist.op_array[j] = -1;
-                       lod_comp->llc_ostlist.op_count = 0;
+               } else if (llc->llc_ostlist.op_array &&
+                          llc->llc_ostlist.op_count) {
+                       for (j = 0; j < llc->llc_ostlist.op_count; j++)
+                               llc->llc_ostlist.op_array[j] = -1;
+                       llc->llc_ostlist.op_count = 0;
                }
        }
 
@@ -4519,27 +5479,32 @@ static int lod_get_default_lmv_striping(const struct lu_env *env,
                                        struct lod_object *lo,
                                        struct lod_default_striping *lds)
 {
-       struct lod_thread_info  *info = lod_env_info(env);
-       struct lmv_user_md_v1   *v1 = NULL;
-       int                      rc;
-       ENTRY;
+       struct lmv_user_md *lmu;
+       int rc;
 
        lds->lds_dir_def_striping_set = 0;
+
        rc = lod_get_default_lmv_ea(env, lo);
        if (rc < 0)
-               RETURN(rc);
+               return rc;
 
-       if (rc < (typeof(rc))sizeof(struct lmv_user_md))
-               RETURN(0);
+       if (rc >= (int)sizeof(*lmu)) {
+               struct lod_thread_info *info = lod_env_info(env);
 
-       v1 = info->lti_ea_store;
+               lmu = info->lti_ea_store;
 
-       lds->lds_dir_def_stripe_count = le32_to_cpu(v1->lum_stripe_count);
-       lds->lds_dir_def_stripe_offset = le32_to_cpu(v1->lum_stripe_offset);
-       lds->lds_dir_def_hash_type = le32_to_cpu(v1->lum_hash_type);
-       lds->lds_dir_def_striping_set = 1;
+               lds->lds_dir_def_stripe_count =
+                               le32_to_cpu(lmu->lum_stripe_count);
+               lds->lds_dir_def_stripe_offset =
+                               le32_to_cpu(lmu->lum_stripe_offset);
+               lds->lds_dir_def_hash_type =
+                               le32_to_cpu(lmu->lum_hash_type);
+               lds->lds_dir_def_max_inherit = lmu->lum_max_inherit;
+               lds->lds_dir_def_max_inherit_rr = lmu->lum_max_inherit_rr;
+               lds->lds_dir_def_striping_set = 1;
+       }
 
-       RETURN(0);
+       return 0;
 }
 
 /**
@@ -4560,7 +5525,16 @@ static int lod_get_default_striping(const struct lu_env *env,
 {
        int rc, rc1;
 
-       rc = lod_get_default_lov_striping(env, lo, lds);
+       rc = lod_get_default_lov_striping(env, lo, lds, NULL);
+       if (lds->lds_def_striping_set) {
+               struct lod_thread_info *info = lod_env_info(env);
+               struct lod_device *d = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+
+               rc = lod_verify_striping(env, d, lo, &info->lti_buf, false);
+               if (rc)
+                       lds->lds_def_striping_set = 0;
+       }
+
        rc1 = lod_get_default_lmv_striping(env, lo, lds);
        if (rc == 0 && rc1 < 0)
                rc = rc1;
@@ -4583,10 +5557,11 @@ static void lod_striping_from_default(struct lod_object *lo,
                                      umode_t mode)
 {
        struct lod_device *d = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
-       struct lov_desc *desc = &d->lod_desc;
        int i, rc;
 
        if (lds->lds_def_striping_set && S_ISREG(mode)) {
+               struct lov_desc *desc = &d->lod_ost_descs.ltd_lov_desc;
+
                rc = lod_alloc_comp_entries(lo, lds->lds_def_mirror_cnt,
                                            lds->lds_def_comp_cnt);
                if (rc != 0)
@@ -4602,8 +5577,10 @@ static void lod_striping_from_default(struct lod_object *lo,
                        struct lod_layout_component *def_comp =
                                                &lds->lds_def_comp_entries[i];
 
-                       CDEBUG(D_LAYOUT, "Inherite from default: size:%hu "
-                              "nr:%u offset:%u pattern %#x %s\n",
+                       CDEBUG(D_LAYOUT,
+                              "inherit "DFID" file layout from default: flags=%#x size=%hu nr=%u offset=%u pattern=%#x pool=%s\n",
+                              PFID(lu_object_fid(&lo->ldo_obj.do_lu)),
+                              def_comp->llc_flags,
                               def_comp->llc_stripe_size,
                               def_comp->llc_stripe_count,
                               def_comp->llc_stripe_offset,
@@ -4642,7 +5619,7 @@ static void lod_striping_from_default(struct lod_object *lo,
                        if (!lo->ldo_is_composite)
                                continue;
 
-                       lod_adjust_stripe_info(obj_comp, desc);
+                       lod_adjust_stripe_info(obj_comp, desc, 0);
                }
        } else if (lds->lds_dir_def_striping_set && S_ISDIR(mode)) {
                if (lo->ldo_dir_stripe_count == 0)
@@ -4651,17 +5628,19 @@ static void lod_striping_from_default(struct lod_object *lo,
                if (lo->ldo_dir_stripe_offset == -1)
                        lo->ldo_dir_stripe_offset =
                                lds->lds_dir_def_stripe_offset;
-               if (lo->ldo_dir_hash_type == 0)
+               if (lo->ldo_dir_hash_type == LMV_HASH_TYPE_UNKNOWN)
                        lo->ldo_dir_hash_type = lds->lds_dir_def_hash_type;
 
-               CDEBUG(D_LAYOUT, "striping from default dir: count:%hu, "
-                      "offset:%u, hash_type:%u\n",
+               CDEBUG(D_LAYOUT,
+                      "inherit "DFID" dir layout from default: count=%hu offset=%u hash_type=%x\n",
+                      PFID(lu_object_fid(&lo->ldo_obj.do_lu)),
                       lo->ldo_dir_stripe_count, lo->ldo_dir_stripe_offset,
                       lo->ldo_dir_hash_type);
        }
 }
 
-static inline bool lod_need_inherit_more(struct lod_object *lo, bool from_root)
+static inline bool lod_need_inherit_more(struct lod_object *lo, bool from_root,
+                                        const char *append_pool)
 {
        struct lod_layout_component *lod_comp;
 
@@ -4681,6 +5660,9 @@ static inline bool lod_need_inherit_more(struct lod_object *lo, bool from_root)
                          lod_comp->llc_stripe_offset == LOV_OFFSET_DEFAULT))
                return true;
 
+       if (append_pool && append_pool[0])
+               return true;
+
        return false;
 }
 
@@ -4690,8 +5672,8 @@ static inline bool lod_need_inherit_more(struct lod_object *lo, bool from_root)
  * This method is used to make a decision on the striping configuration for the
  * object being created. It can be taken from the \a parent object if it exists,
  * or filesystem's default. The resulting configuration (number of stripes,
- * stripe size/offset, pool name, etc) is stored in the object itself and will
- * be used by the methods like ->doo_declare_create().
+ * stripe size/offset, pool name, hash_type, etc.) is stored in the object
+ * itself and will be used by the methods like ->doo_declare_create().
  *
  * \see dt_object_operations::do_ah_init() in the API description for details.
  */
@@ -4703,7 +5685,7 @@ static void lod_ah_init(const struct lu_env *env,
 {
        struct lod_device *d = lu2lod_dev(child->do_lu.lo_dev);
        struct lod_thread_info *info = lod_env_info(env);
-       struct lod_default_striping *lds = &info->lti_def_striping;
+       struct lod_default_striping *lds = lod_lds_buf_get(env);
        struct dt_object *nextp = NULL;
        struct dt_object *nextc;
        struct lod_object *lp = NULL;
@@ -4715,6 +5697,10 @@ static void lod_ah_init(const struct lu_env *env,
 
        LASSERT(child);
 
+       if (ah->dah_append_stripe_count == -1)
+               ah->dah_append_stripe_count =
+                       d->lod_ost_descs.ltd_lov_desc.ld_tgt_count;
+
        if (likely(parent)) {
                nextp = dt_object_child(parent);
                lp = lod_dt_obj(parent);
@@ -4738,14 +5724,20 @@ static void lod_ah_init(const struct lu_env *env,
                /* other default values are 0 */
                lc->ldo_dir_stripe_offset = -1;
 
-               /* get default striping from parent object */
+               /* no default striping configuration is needed for
+                * foreign dirs
+                */
+               if (ah->dah_eadata != NULL && ah->dah_eadata_len != 0 &&
+                   le32_to_cpu(lum1->lum_magic) == LMV_MAGIC_FOREIGN) {
+                       lc->ldo_is_foreign = true;
+                       /* keep stripe_count 0 and stripe_offset -1 */
+                       CDEBUG(D_INFO, "no default striping for foreign dir\n");
+                       RETURN_EXIT;
+               }
+
                if (likely(lp != NULL))
                        lod_get_default_striping(env, lp, lds);
 
-               /* set child default striping info, default value is NULL */
-               if (lds->lds_def_striping_set || lds->lds_dir_def_striping_set)
-                       lc->ldo_def_striping = lds;
-
                /* It should always honour the specified stripes */
                /* Note: old client (< 2.7)might also do lfs mkdir, whose EA
                 * will have old magic. In this case, we should ignore the
@@ -4761,11 +5753,61 @@ static void lod_ah_init(const struct lu_env *env,
                        lc->ldo_dir_hash_type =
                                le32_to_cpu(lum1->lum_hash_type);
                        CDEBUG(D_INFO,
-                              "set dirstripe: count %hu, offset %d, hash %u\n",
+                              "set dirstripe: count %hu, offset %d, hash %x\n",
                                lc->ldo_dir_stripe_count,
                                (int)lc->ldo_dir_stripe_offset,
                                lc->ldo_dir_hash_type);
+
+                       if (d->lod_mdt_descs.ltd_lmv_desc.ld_active_tgt_count &&
+                           lc->ldo_dir_stripe_count < 2 &&
+                           lum1->lum_max_inherit != LMV_INHERIT_NONE) {
+                               /* when filesystem-wide default LMV is set, dirs
+                                * will be created on MDT by space usage, but if
+                                * dir is created with "lfs mkdir -c 1 ...", its
+                                * subdirs should be kept on the same MDT. To
+                                * guarantee this, set default LMV for such dir.
+                                */
+                               lds->lds_dir_def_stripe_count =
+                                       le32_to_cpu(lum1->lum_stripe_count);
+                               /* if "-1" stripe offset is set, save current
+                                * MDT index in default LMV.
+                                */
+                               if (le32_to_cpu(lum1->lum_stripe_offset) ==
+                                   LMV_OFFSET_DEFAULT)
+                                       lds->lds_dir_def_stripe_offset =
+                                               lod2lu_dev(d)->ld_site->ld_seq_site->ss_node_id;
+                               else
+                                       lds->lds_dir_def_stripe_offset =
+                                               le32_to_cpu(lum1->lum_stripe_offset);
+                               lds->lds_dir_def_hash_type =
+                                       le32_to_cpu(lum1->lum_hash_type);
+                               lds->lds_dir_def_max_inherit =
+                                       lum1->lum_max_inherit;
+                               /* it will be decreased by 1 later in setting */
+                               if (lum1->lum_max_inherit >= LMV_INHERIT_END &&
+                                   lum1->lum_max_inherit < LMV_INHERIT_MAX)
+                                       lds->lds_dir_def_max_inherit++;
+                               lds->lds_dir_def_max_inherit_rr =
+                                       lum1->lum_max_inherit_rr;
+                               lds->lds_dir_def_striping_set = 1;
+                               /* don't inherit LOV from ROOT */
+                               if (lds->lds_def_striping_set &&
+                                   fid_is_root(lod_object_fid(lp)))
+                                       lds->lds_def_striping_set = 0;
+                               lc->ldo_def_striping = lds;
+                       } else if (lds->lds_def_striping_set &&
+                                  !fid_is_root(lod_object_fid(lp))) {
+                               /* don't inherit default LMV for "lfs mkdir" */
+                               lds->lds_dir_def_striping_set = 0;
+                               lc->ldo_def_striping = lds;
+                       }
                } else {
+                       /* inherit default striping except ROOT */
+                       if ((lds->lds_def_striping_set ||
+                            lds->lds_dir_def_striping_set) &&
+                           !fid_is_root(lod_object_fid(lp)))
+                               lc->ldo_def_striping = lds;
+
                        /* transfer defaults LMV to new directory */
                        lod_striping_from_default(lc, lds, child_mode);
 
@@ -4774,6 +5816,13 @@ static void lod_ah_init(const struct lu_env *env,
                                lc->ldo_dir_stripe_count = 0;
                }
 
+               /* shrink the stripe count to max_mdt_stripecount if it is -1
+                * and max_mdt_stripecount is not 0
+                */
+               if (lc->ldo_dir_stripe_count == (__u16)(-1) &&
+                   d->lod_max_mdt_stripecount)
+                       lc->ldo_dir_stripe_count = d->lod_max_mdt_stripecount;
+
                /* shrink the stripe_count to the avaible MDT count */
                if (lc->ldo_dir_stripe_count > d->lod_remote_mdt_count + 1 &&
                    !OBD_FAIL_CHECK(OBD_FAIL_LARGE_STRIPE)) {
@@ -4782,7 +5831,12 @@ static void lod_ah_init(const struct lu_env *env,
                                lc->ldo_dir_stripe_count = 0;
                }
 
-               CDEBUG(D_INFO, "final dir stripe [%hu %d %u]\n",
+               if (!lmv_is_known_hash_type(lc->ldo_dir_hash_type))
+                       lc->ldo_dir_hash_type =
+                               (lc->ldo_dir_hash_type & LMV_HASH_FLAG_KNOWN) |
+                               d->lod_mdt_descs.ltd_lmv_desc.ld_pattern;
+
+               CDEBUG(D_INFO, "final dir stripe_count=%hu offset=%d hash=%u\n",
                       lc->ldo_dir_stripe_count,
                       (int)lc->ldo_dir_stripe_offset, lc->ldo_dir_hash_type);
 
@@ -4802,9 +5856,13 @@ static void lod_ah_init(const struct lu_env *env,
         * Try from the parent first.
         */
        if (likely(lp != NULL)) {
-               rc = lod_get_default_lov_striping(env, lp, lds);
-               if (rc == 0)
-                       lod_striping_from_default(lc, lds, child_mode);
+               rc = lod_get_default_lov_striping(env, lp, lds, ah);
+               if (rc == 0 && lds->lds_def_striping_set) {
+                       rc = lod_verify_striping(env, d, lp, &info->lti_buf,
+                                                false);
+                       if (rc == 0)
+                               lod_striping_from_default(lc, lds, child_mode);
+               }
        }
 
        /* Initialize lod_device::lod_md_root object reference */
@@ -4830,10 +5888,18 @@ static void lod_ah_init(const struct lu_env *env,
         *  - parent has plain(v1/v3) default layout, and some attributes
         *    are not specified in the default layout;
         */
-       if (d->lod_md_root != NULL && lod_need_inherit_more(lc, true)) {
-               rc = lod_get_default_lov_striping(env, d->lod_md_root, lds);
+       if (d->lod_md_root != NULL &&
+           lod_need_inherit_more(lc, true, ah->dah_append_pool)) {
+               rc = lod_get_default_lov_striping(env, d->lod_md_root, lds,
+                                                 ah);
+               if (rc || !lds->lds_def_striping_set)
+                       goto out;
+
+               rc = lod_verify_striping(env, d, d->lod_md_root, &info->lti_buf,
+                                        false);
                if (rc)
                        goto out;
+
                if (lc->ldo_comp_cnt == 0) {
                        lod_striping_from_default(lc, lds, child_mode);
                } else if (!lds->lds_def_striping_is_composite) {
@@ -4849,7 +5915,8 @@ static void lod_ah_init(const struct lu_env *env,
                        if (lod_comp->llc_stripe_size <= 0)
                                lod_comp->llc_stripe_size =
                                        def_comp->llc_stripe_size;
-                       if (lod_comp->llc_stripe_offset == LOV_OFFSET_DEFAULT)
+                       if (lod_comp->llc_stripe_offset == LOV_OFFSET_DEFAULT &&
+                           (!lod_comp->llc_pool || !lod_comp->llc_pool[0]))
                                lod_comp->llc_stripe_offset =
                                        def_comp->llc_stripe_offset;
                        if (lod_comp->llc_pool == NULL)
@@ -4861,7 +5928,7 @@ out:
         * fs default striping may not be explicitly set, or historically set
         * in config log, use them.
         */
-       if (lod_need_inherit_more(lc, false)) {
+       if (lod_need_inherit_more(lc, false, ah->dah_append_pool)) {
                if (lc->ldo_comp_cnt == 0) {
                        rc = lod_alloc_comp_entries(lc, 0, 1);
                        if (rc)
@@ -4874,14 +5941,16 @@ out:
                }
                LASSERT(!lc->ldo_is_composite);
                lod_comp = &lc->ldo_comp_entries[0];
-               desc = &d->lod_desc;
-               lod_adjust_stripe_info(lod_comp, desc);
+               desc = &d->lod_ost_descs.ltd_lov_desc;
+               lod_adjust_stripe_info(lod_comp, desc,
+                                      ah->dah_append_stripe_count);
+               if (ah->dah_append_pool && ah->dah_append_pool[0])
+                       lod_obj_set_pool(lc, 0, ah->dah_append_pool);
        }
 
        EXIT;
 }
 
-#define ll_do_div64(aaa,bbb)    do_div((aaa), (bbb))
 /**
  * Size initialization on late striping.
  *
@@ -4945,14 +6014,13 @@ static int lod_declare_init_size(const struct lu_env *env,
                                continue;
 
                        LASSERT(objects != NULL && stripe_size != 0);
-                       /* ll_do_div64(a, b) returns a % b, and a = a / b */
-                       ll_do_div64(size, (__u64)stripe_size);
-                       stripe = ll_do_div64(size, (__u64)stripe_count);
+                       do_div(size, stripe_size);
+                       stripe = do_div(size, stripe_count);
                        LASSERT(objects[stripe] != NULL);
 
                        size = size * stripe_size;
                        offs = attr->la_size;
-                       size += ll_do_div64(offs, stripe_size);
+                       size += do_div(offs, stripe_size);
 
                        attr->la_valid = LA_SIZE;
                        attr->la_size = size;
@@ -5039,6 +6107,48 @@ out:
        RETURN(rc);
 }
 
+/*
+ * Whether subdirectories under \a dt should be created on MDTs by space QoS
+ *
+ * If LMV_HASH_FLAG_SPACE is set on directory default layout, its subdirectories
+ * should be created on MDT by space QoS.
+ *
+ * \param[in] env      execution environment
+ * \param[in] dev      lu device
+ * \param[in] dt       object
+ *
+ * \retval             1 if directory should create subdir by space usage
+ * \retval             0 if not
+ * \retval             -ev if failed
+ */
+static inline int dt_object_qos_mkdir(const struct lu_env *env,
+                                     struct lu_device *dev,
+                                     struct dt_object *dt)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lu_object *obj;
+       struct lod_object *lo;
+       struct lmv_user_md *lmu;
+       int rc;
+
+       obj = lu_object_find_slice(env, dev, lu_object_fid(&dt->do_lu), NULL);
+       if (IS_ERR(obj))
+               return PTR_ERR(obj);
+
+       lo = lu2lod_obj(obj);
+
+       rc = lod_get_default_lmv_ea(env, lo);
+       dt_object_put(env, dt);
+       if (rc <= 0)
+               return rc;
+
+       if (rc < (int)sizeof(*lmu))
+               return -EINVAL;
+
+       lmu = info->lti_ea_store;
+       return le32_to_cpu(lmu->lum_stripe_offset) == LMV_OFFSET_DEFAULT;
+}
+
 /**
  * Implementation of dt_object_operations::do_declare_create.
  *
@@ -5102,24 +6212,15 @@ static int lod_declare_create(const struct lu_env *env, struct dt_object *dt,
                        if (OBD_FAIL_CHECK(OBD_FAIL_MDS_STALE_DIR_LAYOUT))
                                GOTO(out, rc = -EREMOTE);
 
-                       if (lo->ldo_dir_stripe_offset == -1) {
-                               /* child and parent should be in the same MDT */
-                               if (hint->dah_parent != NULL &&
-                                   dt_object_remote(hint->dah_parent))
-                                       GOTO(out, rc = -EREMOTE);
-                       } else if (lo->ldo_dir_stripe_offset !=
-                                  ss->ss_node_id) {
+                       if (lo->ldo_dir_stripe_offset != LMV_OFFSET_DEFAULT &&
+                           lo->ldo_dir_stripe_offset != ss->ss_node_id) {
                                struct lod_device *lod;
-                               struct lod_tgt_descs *ltd;
-                               struct lod_tgt_desc *tgt = NULL;
+                               struct lu_tgt_desc *mdt = NULL;
                                bool found_mdt = false;
-                               int i;
 
                                lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
-                               ltd = &lod->lod_mdt_descs;
-                               cfs_foreach_bit(ltd->ltd_tgt_bitmap, i) {
-                                       tgt = LTD_TGT(ltd, i);
-                                       if (tgt->ltd_index ==
+                               lod_foreach_mdt(lod, mdt) {
+                                       if (mdt->ltd_index ==
                                                lo->ldo_dir_stripe_offset) {
                                                found_mdt = true;
                                                break;
@@ -5228,7 +6329,10 @@ int lod_striped_create(const struct lu_env *env, struct dt_object *dt,
        int     rc = 0, i, j;
        ENTRY;
 
-       LASSERT(lo->ldo_comp_cnt != 0 && lo->ldo_comp_entries != NULL);
+       mutex_lock(&lo->ldo_layout_mutex);
+
+       LASSERT((lo->ldo_comp_cnt != 0 && lo->ldo_comp_entries != NULL) ||
+               lo->ldo_is_foreign);
 
        mirror_id = 0; /* non-flr file's mirror_id is 0 */
        if (lo->ldo_mirror_count > 1) {
@@ -5285,18 +6389,40 @@ int lod_striped_create(const struct lu_env *env, struct dt_object *dt,
        if (rc)
                GOTO(out, rc);
 
+       lo->ldo_comp_cached = 1;
+
        rc = lod_generate_and_set_lovea(env, lo, th);
        if (rc)
                GOTO(out, rc);
 
-       lo->ldo_comp_cached = 1;
+       mutex_unlock(&lo->ldo_layout_mutex);
+
        RETURN(0);
 
 out:
-       lod_striping_free(env, lo);
+       lod_striping_free_nolock(env, lo);
+       mutex_unlock(&lo->ldo_layout_mutex);
+
        RETURN(rc);
 }
 
+static inline bool lod_obj_is_dom(struct dt_object *dt)
+{
+       struct lod_object *lo = lod_dt_obj(dt);
+
+       if (!dt_object_exists(dt_object_child(dt)))
+               return false;
+
+       if (S_ISDIR(dt->do_lu.lo_header->loh_attr))
+               return false;
+
+       if (!lo->ldo_comp_cnt)
+               return false;
+
+       return (lov_pattern(lo->ldo_comp_entries[0].llc_pattern) ==
+               LOV_PATTERN_MDT);
+}
+
 /**
  * Implementation of dt_object_operations::do_create.
  *
@@ -5319,7 +6445,8 @@ static int lod_create(const struct lu_env *env, struct dt_object *dt,
                RETURN(rc);
 
        if (S_ISREG(dt->do_lu.lo_header->loh_attr) &&
-           lod_obj_is_striped(dt) && dof->u.dof_reg.striped != 0) {
+           (lod_obj_is_striped(dt) || lod_obj_is_dom(dt)) &&
+           dof->u.dof_reg.striped != 0) {
                LASSERT(lod_dt_obj(dt)->ldo_comp_cached == 0);
                rc = lod_striped_create(env, dt, attr, dof, th);
        }
@@ -5335,11 +6462,12 @@ lod_obj_stripe_destroy_cb(const struct lu_env *env, struct lod_object *lo,
 {
        if (data->locd_declare)
                return lod_sub_declare_destroy(env, dt, th);
-       else if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_SPEOBJ) ||
-                stripe_idx == cfs_fail_val)
+
+       if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_SPEOBJ) ||
+           stripe_idx == cfs_fail_val)
                return lod_sub_destroy(env, dt, th);
-       else
-               return 0;
+
+       return 0;
 }
 
 /**
@@ -5356,11 +6484,13 @@ lod_obj_stripe_destroy_cb(const struct lu_env *env, struct lod_object *lo,
 static int lod_declare_destroy(const struct lu_env *env, struct dt_object *dt,
                               struct thandle *th)
 {
-       struct dt_object   *next = dt_object_child(dt);
-       struct lod_object  *lo = lod_dt_obj(dt);
+       struct dt_object *next = dt_object_child(dt);
+       struct lod_object *lo = lod_dt_obj(dt);
        struct lod_thread_info *info = lod_env_info(env);
-       char               *stripe_name = info->lti_key;
-       int                 rc, i;
+       struct dt_object *stripe;
+       char *stripe_name = info->lti_key;
+       int rc, i;
+
        ENTRY;
 
        /*
@@ -5380,13 +6510,17 @@ static int lod_declare_destroy(const struct lu_env *env, struct dt_object *dt,
                        RETURN(rc);
 
                for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+                       stripe = lo->ldo_stripe[i];
+                       if (!stripe)
+                               continue;
+
                        rc = lod_sub_declare_ref_del(env, next, th);
                        if (rc != 0)
                                RETURN(rc);
 
-                       snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
-                               PFID(lu_object_fid(&lo->ldo_stripe[i]->do_lu)),
-                               i);
+                       snprintf(stripe_name, sizeof(info->lti_key),
+                                DFID":%d",
+                                PFID(lu_object_fid(&stripe->do_lu)), i);
                        rc = lod_sub_declare_delete(env, next,
                                        (const struct dt_key *)stripe_name, th);
                        if (rc != 0)
@@ -5411,14 +6545,18 @@ static int lod_declare_destroy(const struct lu_env *env, struct dt_object *dt,
        /* declare destroy all striped objects */
        if (S_ISDIR(dt->do_lu.lo_header->loh_attr)) {
                for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-                       if (lo->ldo_stripe[i] == NULL)
+                       stripe = lo->ldo_stripe[i];
+                       if (!stripe)
                                continue;
 
-                       rc = lod_sub_declare_ref_del(env, lo->ldo_stripe[i],
-                                                    th);
+                       if (!dt_object_exists(stripe))
+                               continue;
 
-                       rc = lod_sub_declare_destroy(env, lo->ldo_stripe[i],
-                                                    th);
+                       rc = lod_sub_declare_ref_del(env, stripe, th);
+                       if (rc != 0)
+                               break;
+
+                       rc = lod_sub_declare_destroy(env, stripe, th);
                        if (rc != 0)
                                break;
                }
@@ -5448,9 +6586,11 @@ static int lod_destroy(const struct lu_env *env, struct dt_object *dt,
        struct dt_object  *next = dt_object_child(dt);
        struct lod_object *lo = lod_dt_obj(dt);
        struct lod_thread_info *info = lod_env_info(env);
-       char               *stripe_name = info->lti_key;
-       unsigned int       i;
-       int                rc;
+       char *stripe_name = info->lti_key;
+       struct dt_object *stripe;
+       unsigned int i;
+       int rc;
+
        ENTRY;
 
        /* destroy sub-stripe of master object */
@@ -5461,17 +6601,20 @@ static int lod_destroy(const struct lu_env *env, struct dt_object *dt,
                        RETURN(rc);
 
                for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+                       stripe = lo->ldo_stripe[i];
+                       if (!stripe)
+                               continue;
+
                        rc = lod_sub_ref_del(env, next, th);
                        if (rc != 0)
                                RETURN(rc);
 
                        snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
-                               PFID(lu_object_fid(&lo->ldo_stripe[i]->do_lu)),
-                               i);
+                               PFID(lu_object_fid(&stripe->do_lu)), i);
 
                        CDEBUG(D_INFO, DFID" delete stripe %s "DFID"\n",
                               PFID(lu_object_fid(&dt->do_lu)), stripe_name,
-                              PFID(lu_object_fid(&lo->ldo_stripe[i]->do_lu)));
+                              PFID(lu_object_fid(&stripe->do_lu)));
 
                        rc = lod_sub_delete(env, next,
                                       (const struct dt_key *)stripe_name, th);
@@ -5494,20 +6637,22 @@ static int lod_destroy(const struct lu_env *env, struct dt_object *dt,
        /* destroy all striped objects */
        if (S_ISDIR(dt->do_lu.lo_header->loh_attr)) {
                for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
-                       if (lo->ldo_stripe[i] == NULL)
+                       stripe = lo->ldo_stripe[i];
+                       if (!stripe)
+                               continue;
+
+                       if (!dt_object_exists(stripe))
                                continue;
+
                        if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_SPEOBJ) ||
                            i == cfs_fail_val) {
-                               dt_write_lock(env, lo->ldo_stripe[i],
-                                             MOR_TGT_CHILD);
-                               rc = lod_sub_ref_del(env, lo->ldo_stripe[i],
-                                                    th);
-                               dt_write_unlock(env, lo->ldo_stripe[i]);
+                               dt_write_lock(env, stripe, DT_TGT_CHILD);
+                               rc = lod_sub_ref_del(env, stripe, th);
+                               dt_write_unlock(env, stripe);
                                if (rc != 0)
                                        break;
 
-                               rc = lod_sub_destroy(env, lo->ldo_stripe[i],
-                                                    th);
+                               rc = lod_sub_destroy(env, stripe, th);
                                if (rc != 0)
                                        break;
                        }
@@ -5615,8 +6760,10 @@ static int lod_object_unlock(const struct lu_env *env, struct dt_object *dt,
         * NB, ha_count may not equal to ldo_dir_stripe_count, because dir
         * layout may change, e.g., shrink dir layout after migration.
         */
-       for (i = 0; i < lo->ldo_dir_stripe_count; i++)
-               dt_invalidate(env, lo->ldo_stripe[i]);
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               if (lo->ldo_stripe[i])
+                       dt_invalidate(env, lo->ldo_stripe[i]);
+       }
 
        slave_locks_size = offsetof(typeof(*slave_locks),
                                    ha_handles[slave_locks->ha_count]);
@@ -5677,17 +6824,19 @@ static int lod_object_lock(const struct lu_env *env,
        for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
                struct lustre_handle lockh;
                struct ldlm_res_id *res_id;
+               struct dt_object *stripe;
+
+               stripe = lo->ldo_stripe[i];
+               if (!stripe)
+                       continue;
 
                res_id = &lod_env_info(env)->lti_res_id;
-               fid_build_reg_res_name(lu_object_fid(&lo->ldo_stripe[i]->do_lu),
-                                      res_id);
+               fid_build_reg_res_name(lu_object_fid(&stripe->do_lu), res_id);
                einfo->ei_res_id = res_id;
 
-               LASSERT(lo->ldo_stripe[i] != NULL);
-               if (dt_object_remote(lo->ldo_stripe[i])) {
+               if (dt_object_remote(stripe)) {
                        set_bit(i, (void *)slave_locks->ha_map);
-                       rc = dt_object_lock(env, lo->ldo_stripe[i], &lockh,
-                                           einfo, policy);
+                       rc = dt_object_lock(env, stripe, &lockh, einfo, policy);
                } else {
                        struct ldlm_namespace *ns = einfo->ei_namespace;
                        ldlm_blocking_callback blocking = einfo->ei_cb_local_bl;
@@ -5699,7 +6848,7 @@ static int lod_object_lock(const struct lu_env *env,
                                dlmflags |= LDLM_FL_COS_INCOMPAT;
 
                        LASSERT(ns != NULL);
-                       rc = ldlm_cli_enqueue_local(ns, res_id, LDLM_IBITS,
+                       rc = ldlm_cli_enqueue_local(env, ns, res_id, LDLM_IBITS,
                                                    policy, einfo->ei_mode,
                                                    &dlmflags, blocking,
                                                    completion, NULL,
@@ -5731,33 +6880,10 @@ static int lod_invalidate(const struct lu_env *env, struct dt_object *dt)
        return dt_invalidate(env, dt_object_child(dt));
 }
 
-static int lod_layout_data_init(struct lod_thread_info *info, __u32 comp_cnt)
-{
-       ENTRY;
-
-       /* clear memory region that will be used for layout change */
-       memset(&info->lti_layout_attr, 0, sizeof(struct lu_attr));
-       info->lti_count = 0;
-
-       if (info->lti_comp_size >= comp_cnt)
-               RETURN(0);
-
-       if (info->lti_comp_size > 0) {
-               OBD_FREE(info->lti_comp_idx,
-                        info->lti_comp_size * sizeof(__u32));
-               info->lti_comp_size = 0;
-       }
-
-       OBD_ALLOC(info->lti_comp_idx, comp_cnt * sizeof(__u32));
-       if (!info->lti_comp_idx)
-               RETURN(-ENOMEM);
-
-       info->lti_comp_size = comp_cnt;
-       RETURN(0);
-}
-
 static int lod_declare_instantiate_components(const struct lu_env *env,
-               struct lod_object *lo, struct thandle *th)
+                                             struct lod_object *lo,
+                                             struct thandle *th,
+                                             __u64 reserve)
 {
        struct lod_thread_info *info = lod_env_info(env);
        int i;
@@ -5768,7 +6894,7 @@ static int lod_declare_instantiate_components(const struct lu_env *env,
 
        for (i = 0; i < info->lti_count; i++) {
                rc = lod_qos_prep_create(env, lo, NULL, th,
-                                        info->lti_comp_idx[i]);
+                                        info->lti_comp_idx[i], reserve);
                if (rc)
                        break;
        }
@@ -5782,119 +6908,690 @@ static int lod_declare_instantiate_components(const struct lu_env *env,
        RETURN(rc);
 }
 
-static int lod_declare_update_plain(const struct lu_env *env,
-               struct lod_object *lo, struct layout_intent *layout,
-               const struct lu_buf *buf, struct thandle *th)
+/**
+ * Check OSTs for an existing component for further extension
+ *
+ * Checks if OSTs are still healthy and not out of space.  Gets free space
+ * on OSTs (relative to allocation watermark rmb_low) and compares to
+ * the proposed new_end for this component.
+ *
+ * Decides whether or not to extend a component on its current OSTs.
+ *
+ * \param[in] env              execution environment for this thread
+ * \param[in] lo               object we're checking
+ * \param[in] index            index of this component
+ * \param[in] extension_size   extension size for this component
+ * \param[in] extent           layout extent for requested operation
+ * \param[in] comp_extent      extension component extent
+ * \param[in] write            if this is write operation
+ *
+ * \retval     true - OK to extend on current OSTs
+ * \retval     false - do not extend on current OSTs
+ */
+static bool lod_sel_osts_allowed(const struct lu_env *env,
+                                struct lod_object *lo,
+                                int index, __u64 reserve,
+                                struct lu_extent *extent,
+                                struct lu_extent *comp_extent, int write)
 {
-       struct lod_thread_info *info = lod_env_info(env);
-       struct lod_device *d = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
-       struct lod_layout_component *lod_comp;
-       struct lov_comp_md_v1 *comp_v1 = NULL;
-       bool replay = false;
+       struct lod_layout_component *lod_comp = &lo->ldo_comp_entries[index];
+       struct lod_device *lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+       struct lod_thread_info *tinfo = lod_env_info(env);
+       struct obd_statfs *sfs = &tinfo->lti_osfs;
+       __u64 available = 0;
+       bool ret = true;
        int i, rc;
-       ENTRY;
-
-       LASSERT(lo->ldo_flr_state == LCM_FL_NONE);
 
-       /*
-        * In case the client is passing lovea, which only happens during
-        * the replay of layout intent write RPC for now, we may need to
-        * parse the lovea and apply new layout configuration.
-        */
-       if (buf && buf->lb_len)  {
-               struct lov_user_md_v1 *v1 = buf->lb_buf;
+       ENTRY;
 
-               if (v1->lmm_magic != (LOV_MAGIC_DEFINED | LOV_MAGIC_COMP_V1) &&
-                   v1->lmm_magic != __swab32(LOV_MAGIC_DEFINED |
-                                             LOV_MAGIC_COMP_V1)) {
-                       CERROR("%s: the replay buffer of layout extend "
-                              "(magic %#x) does not contain expected "
-                              "composite layout.\n",
-                              lod2obd(d)->obd_name, v1->lmm_magic);
-                       GOTO(out, rc = -EINVAL);
-               }
+       LASSERT(lod_comp->llc_stripe_count != 0);
 
-               rc = lod_use_defined_striping(env, lo, buf);
-               if (rc)
-                       GOTO(out, rc);
-               lo->ldo_comp_cached = 1;
+       lod_getref(&lod->lod_ost_descs);
+       for (i = 0; i < lod_comp->llc_stripe_count; i++) {
+               int index = lod_comp->llc_ost_indices[i];
+               struct lod_tgt_desc *ost = OST_TGT(lod, index);
+               struct obd_statfs_info info = { 0 };
+               int j, repeated = 0;
 
-               rc = lod_get_lov_ea(env, lo);
-               if (rc <= 0)
-                       GOTO(out, rc);
-               /* old on-disk EA is stored in info->lti_buf */
-               comp_v1 = (struct lov_comp_md_v1 *)info->lti_buf.lb_buf;
-               replay = true;
-       } else {
-               /* non replay path */
-               rc = lod_striping_load(env, lo);
-               if (rc)
-                       GOTO(out, rc);
-       }
+               LASSERT(ost);
 
-       /* Make sure defined layout covers the requested write range. */
-       lod_comp = &lo->ldo_comp_entries[lo->ldo_comp_cnt - 1];
-       if (lo->ldo_comp_cnt > 1 &&
-           lod_comp->llc_extent.e_end != OBD_OBJECT_EOF &&
-           lod_comp->llc_extent.e_end < layout->li_extent.e_end) {
-               CDEBUG(replay ? D_ERROR : D_LAYOUT,
-                      "%s: the defined layout [0, %#llx) does not covers "
-                      "the write range "DEXT"\n",
-                      lod2obd(d)->obd_name, lod_comp->llc_extent.e_end,
-                      PEXT(&layout->li_extent));
-               GOTO(out, rc = -EINVAL);
-       }
+               /* Get the number of times this OST repeats in this component.
+                * Note: inter-component repeats are not counted as this is
+                * considered as a rare case: we try to not repeat OST in other
+                * components if possible. */
+               for (j = 0; j < lod_comp->llc_stripe_count; j++) {
+                       if (index != lod_comp->llc_ost_indices[j])
+                               continue;
 
-       CDEBUG(D_LAYOUT, "%s: "DFID": instantiate components "DEXT"\n",
-              lod2obd(d)->obd_name, PFID(lod_object_fid(lo)),
-              PEXT(&layout->li_extent));
+                       /* already handled */
+                       if (j < i)
+                               break;
 
-       /*
-        * Iterate ld->ldo_comp_entries, find the component whose extent under
-        * the write range and not instantianted.
-        */
-       for (i = 0; i < lo->ldo_comp_cnt; i++) {
-               lod_comp = &lo->ldo_comp_entries[i];
+                       repeated++;
+               }
+               if (j < lod_comp->llc_stripe_count)
+                       continue;
 
-               if (lod_comp->llc_extent.e_start >= layout->li_extent.e_end)
+               if (!test_bit(index, lod->lod_ost_bitmap)) {
+                       CDEBUG(D_LAYOUT, "ost %d no longer present\n", index);
+                       ret = false;
                        break;
+               }
 
-               if (!replay) {
-                       if (lod_comp_inited(lod_comp))
-                               continue;
-               } else {
-                       /**
-                        * In replay path, lod_comp is the EA passed by
-                        * client replay buffer,  comp_v1 is the pre-recovery
-                        * on-disk EA, we'd sift out those components which
-                        * were init-ed in the on-disk EA.
-                        */
-                       if (le32_to_cpu(comp_v1->lcm_entries[i].lcme_flags) &
-                           LCME_FL_INIT)
-                               continue;
+               rc = dt_statfs_info(env, ost->ltd_tgt, sfs, &info);
+               if (rc) {
+                       CDEBUG(D_LAYOUT, "statfs failed for ost %d, error %d\n",
+                              index, rc);
+                       ret = false;
+                       break;
                }
-               /*
-                * this component hasn't instantiated in normal path, or during
-                * replay it needs replay the instantiation.
-                */
 
-               /* A released component is being extended */
-               if (lod_comp->llc_pattern & LOV_PATTERN_F_RELEASED)
-                       GOTO(out, rc = -EINVAL);
+               if (sfs->os_state & OS_STATFS_ENOSPC ||
+                   sfs->os_state & OS_STATFS_READONLY ||
+                   sfs->os_state & OS_STATFS_DEGRADED) {
+                       CDEBUG(D_LAYOUT, "ost %d is not availble for SEL "
+                              "extension, state %u\n", index, sfs->os_state);
+                       ret = false;
+                       break;
+               }
 
-               LASSERT(info->lti_comp_idx != NULL);
-               info->lti_comp_idx[info->lti_count++] = i;
+               /* In bytes */
+               available = sfs->os_bavail * sfs->os_bsize;
+               /* 'available' is relative to the allocation threshold */
+               available -= (__u64) info.os_reserved_mb_low << 20;
+
+               CDEBUG(D_LAYOUT, "ost %d lowwm: %d highwm: %d, "
+                      "%llu %% blocks available, %llu %% blocks free\n",
+                      index, info.os_reserved_mb_low, info.os_reserved_mb_high,
+                      (100ull * sfs->os_bavail) / sfs->os_blocks,
+                      (100ull * sfs->os_bfree) / sfs->os_blocks);
+
+               if (reserve * repeated > available) {
+                       ret = false;
+                       CDEBUG(D_LAYOUT, "low space on ost %d, available %llu "
+                              "< extension size %llu repeated %d\n", index,
+                              available, reserve, repeated);
+                       break;
+               }
        }
+       lod_putref(lod, &lod->lod_ost_descs);
 
-       if (info->lti_count == 0)
-               RETURN(-EALREADY);
+       RETURN(ret);
+}
+
+/**
+ * Adjust extents after component removal
+ *
+ * When we remove an extension component, we move the start of the next
+ * component to match the start of the extension component, so no space is left
+ * without layout.
+ *
+ * \param[in] env      execution environment for this thread
+ * \param[in] lo       object
+ * \param[in] max_comp layout component
+ * \param[in] index    index of this component
+ *
+ * \retval             0 on success
+ * \retval             negative errno on error
+ */
+static void lod_sel_adjust_extents(const struct lu_env *env,
+                                  struct lod_object *lo,
+                                  int max_comp, int index)
+{
+       struct lod_layout_component *lod_comp = NULL;
+       struct lod_layout_component *next = NULL;
+       struct lod_layout_component *prev = NULL;
+       __u64 new_start = 0;
+       __u64 start;
+       int i;
+
+       /* Extension space component */
+       lod_comp = &lo->ldo_comp_entries[index];
+       next = &lo->ldo_comp_entries[index + 1];
+       prev = &lo->ldo_comp_entries[index - 1];
+
+       LASSERT(lod_comp != NULL && prev != NULL && next != NULL);
+       LASSERT(lod_comp->llc_flags & LCME_FL_EXTENSION);
+
+       /* Previous is being removed */
+       if (prev && prev->llc_id == LCME_ID_INVAL)
+               new_start = prev->llc_extent.e_start;
+       else
+               new_start = lod_comp->llc_extent.e_start;
+
+       for (i = index + 1; i < max_comp; i++) {
+               lod_comp = &lo->ldo_comp_entries[i];
+
+               start = lod_comp->llc_extent.e_start;
+               lod_comp->llc_extent.e_start = new_start;
+
+               /* We only move zero length extendable components */
+               if (!(start == lod_comp->llc_extent.e_end))
+                       break;
+
+               LASSERT(!(lod_comp->llc_flags & LCME_FL_INIT));
+
+               lod_comp->llc_extent.e_end = new_start;
+       }
+}
+
+/* Calculate the proposed 'new end' for a component we're extending */
+static __u64 lod_extension_new_end(__u64 extension_size, __u64 extent_end,
+                                  __u32 stripe_size, __u64 component_end,
+                                  __u64 extension_end)
+{
+       __u64 new_end;
+
+       LASSERT(extension_size != 0 && stripe_size != 0);
+
+       /* Round up to extension size */
+       if (extent_end == OBD_OBJECT_EOF) {
+               new_end = OBD_OBJECT_EOF;
+       } else {
+               /* Add at least extension_size to the previous component_end,
+                * covering the req layout extent */
+               new_end = max(extent_end - component_end, extension_size);
+               new_end = roundup(new_end, extension_size);
+               new_end += component_end;
+
+               /* Component end must be min stripe size aligned */
+               if (new_end % stripe_size) {
+                       CDEBUG(D_LAYOUT, "new component end is not aligned "
+                              "by the stripe size %u: [%llu, %llu) ext size "
+                              "%llu new end %llu, aligning\n",
+                              stripe_size, component_end, extent_end,
+                              extension_size, new_end);
+                       new_end = roundup(new_end, stripe_size);
+               }
+
+               /* Overflow */
+               if (new_end < extent_end)
+                       new_end = OBD_OBJECT_EOF;
+       }
+
+       /* Don't extend past the end of the extension component */
+       if (new_end > extension_end)
+               new_end = extension_end;
+
+       return new_end;
+}
+
+/**
+ * Calculate the exact reservation (per-OST extension_size) on the OSTs being
+ * instantiated. It needs to be calculated in advance and taken into account at
+ * the instantiation time, because otherwise lod_statfs_and_check() may consider
+ * an OST as OK, but SEL needs its extension_size to fit the free space and the
+ * OST may turn out to be low-on-space, thus inappropriate OST may be used and
+ * ENOSPC occurs.
+ *
+ * \param[in] lod_comp         lod component we are checking
+ *
+ * \retval     size to reserved on each OST of lod_comp's stripe.
+ */
+static __u64 lod_sel_stripe_reserved(struct lod_layout_component *lod_comp)
+{
+       /* extension_size is file level, so we must divide by stripe count to
+        * compare it to available space on a single OST */
+       return  lod_comp->llc_stripe_size * SEL_UNIT_SIZE /
+               lod_comp->llc_stripe_count;
+}
+
+/* As lod_sel_handler() could be re-entered for the same component several
+ * times, this is the data for the next call. Fields could be changed to
+ * component indexes when needed, (e.g. if there is no need to instantiate
+ * all the previous components up to the current position) to tell the caller
+ * where to start over from. */
+struct sel_data {
+       int sd_force;
+       int sd_repeat;
+};
+
+/**
+ * Process extent updates for a particular layout component
+ *
+ * Handle layout updates for a particular extension space component touched by
+ * a layout update operation.  Core function of self-extending PFL feature.
+ *
+ * In general, this function processes exactly *one* stage of an extension
+ * operation, modifying the layout accordingly, then returns to the caller.
+ * The caller is responsible for restarting processing with the new layout,
+ * which may repeatedly return to this function until the extension updates
+ * are complete.
+ *
+ * This function does one of a few things to the layout:
+ * 1. Extends the component before the current extension space component to
+ * allow it to accomodate the requested operation (if space/policy permit that
+ * component to continue on its current OSTs)
+ *
+ * 2. If extension of the existing component fails, we do one of two things:
+ *    a. If there is a component after the extension space, we remove the
+ *       extension space component, move the start of the next component down
+ *       accordingly, then notify the caller to restart processing w/the new
+ *       layout.
+ *    b. If there is no following component, we try repeating the current
+ *       component, creating a new component using the current one as a
+ *       template (keeping its stripe properties but not specific striping),
+ *       and try assigning striping for this component.  If there is sufficient
+ *       free space on the OSTs chosen for this component, it is instantiated
+ *       and i/o continues there.
+ *
+ *       If there is not sufficient space on the new OSTs, we remove this new
+ *       component & extend the current component.
+ *
+ * Note further that uninited components followed by extension space can be zero
+ * length meaning that we will try to extend them before initializing them, and
+ * if that fails, they will be removed without initialization.
+ *
+ * 3. If we extend to/beyond the end of an extension space component, that
+ * component is exhausted (all of its range has been given to real components),
+ * so we remove it and restart processing.
+ *
+ * \param[in] env              execution environment for this thread
+ * \param[in,out] lo           object to update the layout of
+ * \param[in] extent           layout extent for requested operation, update
+ *                             layout to fit this operation
+ * \param[in] th               transaction handle for this operation
+ * \param[in,out] max_comp     the highest comp for the portion of the layout
+ *                             we are operating on (For FLR, the chosen
+ *                             replica).  Updated because we may remove
+ *                             components.
+ * \param[in] index            index of the extension space component we're
+ *                             working on
+ * \param[in] write            if this is write op
+ * \param[in,out] force                if the extension is to be forced; set here
+                               to force it on the 2nd call for the same
+                               extension component
+ *
+ * \retval     0 on success
+ * \retval     negative errno on error
+ */
+static int lod_sel_handler(const struct lu_env *env,
+                         struct lod_object *lo,
+                         struct lu_extent *extent,
+                         struct thandle *th, int *max_comp,
+                         int index, int write,
+                         struct sel_data *sd)
+{
+       struct lod_device *d = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_layout_component *lod_comp;
+       struct lod_layout_component *prev;
+       struct lod_layout_component *next = NULL;
+       __u64 extension_size, reserve;
+       __u64 new_end = 0;
+       bool repeated;
+       int change = 0;
+       int rc = 0;
+       ENTRY;
+
+       /* First component cannot be extension space */
+       if (index == 0) {
+               CERROR("%s: "DFID" first component cannot be extension space\n",
+                      lod2obd(d)->obd_name, PFID(lod_object_fid(lo)));
+               RETURN(-EINVAL);
+       }
+
+       lod_comp = &lo->ldo_comp_entries[index];
+       prev = &lo->ldo_comp_entries[index - 1];
+       if ((index + 1) < *max_comp)
+               next = &lo->ldo_comp_entries[index + 1];
+
+       /* extension size uses the stripe size field as KiB */
+       extension_size = lod_comp->llc_stripe_size * SEL_UNIT_SIZE;
+
+       CDEBUG(D_LAYOUT, "prev start %llu, extension start %llu, extension end"
+              " %llu, extension size %llu\n", prev->llc_extent.e_start,
+              lod_comp->llc_extent.e_start, lod_comp->llc_extent.e_end,
+              extension_size);
+
+       /* Two extension space components cannot be adjacent & extension space
+        * components cannot be init */
+       if ((prev->llc_flags & LCME_FL_EXTENSION) ||
+           !(ergo(next, !(next->llc_flags & LCME_FL_EXTENSION))) ||
+            lod_comp_inited(lod_comp)) {
+               CERROR("%s: "DFID" invalid extension space components\n",
+                      lod2obd(d)->obd_name, PFID(lod_object_fid(lo)));
+               RETURN(-EINVAL);
+       }
+
+       reserve = lod_sel_stripe_reserved(lod_comp);
+
+       if (!prev->llc_stripe) {
+               CDEBUG(D_LAYOUT, "Previous component not inited\n");
+               info->lti_count = 1;
+               info->lti_comp_idx[0] = index - 1;
+               rc = lod_declare_instantiate_components(env, lo, th, reserve);
+               /* ENOSPC tells us we can't use this component.  If there is
+                * a next or we are repeating, we either spill over (next) or
+                * extend the original comp (repeat).  Otherwise, return the
+                * error to the user. */
+               if (rc == -ENOSPC && (next || sd->sd_repeat))
+                       rc = 1;
+               if (rc < 0)
+                       RETURN(rc);
+       }
+
+       if (sd->sd_force == 0 && rc == 0)
+               rc = !lod_sel_osts_allowed(env, lo, index - 1, reserve, extent,
+                                          &lod_comp->llc_extent, write);
+
+       repeated = !!(sd->sd_repeat);
+       sd->sd_repeat = 0;
+       sd->sd_force = 0;
+
+       /* Extend previous component */
+       if (rc == 0) {
+               new_end = lod_extension_new_end(extension_size, extent->e_end,
+                                               prev->llc_stripe_size,
+                                               prev->llc_extent.e_end,
+                                               lod_comp->llc_extent.e_end);
+
+               CDEBUG(D_LAYOUT, "new end %llu\n", new_end);
+               lod_comp->llc_extent.e_start = new_end;
+               prev->llc_extent.e_end = new_end;
+
+               if (prev->llc_extent.e_end == lod_comp->llc_extent.e_end) {
+                       CDEBUG(D_LAYOUT, "Extension component exhausted\n");
+                       lod_comp->llc_id = LCME_ID_INVAL;
+                       change--;
+               }
+       } else {
+               /* rc == 1, failed to extend current component */
+               LASSERT(rc == 1);
+               if (next) {
+                       /* Normal 'spillover' case - Remove the extension
+                        * space component & bring down the start of the next
+                        * component. */
+                       lod_comp->llc_id = LCME_ID_INVAL;
+                       change--;
+                       if (!(prev->llc_flags & LCME_FL_INIT)) {
+                               prev->llc_id = LCME_ID_INVAL;
+                               change--;
+                       }
+                       lod_sel_adjust_extents(env, lo, *max_comp, index);
+               } else if (lod_comp_inited(prev)) {
+                       /* If there is no next, and the previous component is
+                        * INIT'ed, try repeating the previous component. */
+                       LASSERT(repeated == 0);
+                       rc = lod_layout_repeat_comp(env, lo, index - 1);
+                       if (rc < 0)
+                               RETURN(rc);
+                       change++;
+                       /* The previous component is a repeated component.
+                        * Record this so we don't keep trying to repeat it. */
+                       sd->sd_repeat = 1;
+               } else {
+                       /* If the previous component is not INIT'ed, this may
+                        * be a component we have just instantiated but failed
+                        * to extend. Or even a repeated component we failed
+                        * to prepare a striping for. Do not repeat but instead
+                        * remove the repeated component & force the extention
+                        * of the original one */
+                       sd->sd_force = 1;
+                       if (repeated) {
+                               prev->llc_id = LCME_ID_INVAL;
+                               change--;
+                       }
+               }
+       }
+
+       if (change < 0) {
+               rc = lod_layout_del_prep_layout(env, lo, NULL);
+               if (rc < 0)
+                       RETURN(rc);
+               LASSERTF(-rc == change,
+                        "number deleted %d != requested %d\n", -rc,
+                        change);
+       }
+       *max_comp = *max_comp + change;
+
+       /* lod_del_prep_layout reallocates ldo_comp_entries, so we must
+        * refresh these pointers before using them */
+       lod_comp = &lo->ldo_comp_entries[index];
+       prev = &lo->ldo_comp_entries[index - 1];
+       CDEBUG(D_LAYOUT, "After extent updates: prev start %llu, current start "
+              "%llu, current end %llu max_comp %d ldo_comp_cnt %d\n",
+              prev->llc_extent.e_start, lod_comp->llc_extent.e_start,
+              lod_comp->llc_extent.e_end, *max_comp, lo->ldo_comp_cnt);
+
+       /* Layout changed successfully */
+       RETURN(0);
+}
+
+/**
+ * Declare layout extent updates
+ *
+ * Handles extensions.  Identifies extension components touched by current
+ * operation and passes them to processing function.
+ *
+ * Restarts with updated layouts from the processing function until the current
+ * operation no longer touches an extension space component.
+ *
+ * \param[in] env      execution environment for this thread
+ * \param[in,out] lo   object to update the layout of
+ * \param[in] extent   layout extent for requested operation, update layout to
+ *                     fit this operation
+ * \param[in] th       transaction handle for this operation
+ * \param[in] pick     identifies chosen mirror for FLR layouts
+ * \param[in] write    if this is write op
+ *
+ * \retval     1 on layout changed, 0 on no change
+ * \retval     negative errno on error
+ */
+static int lod_declare_update_extents(const struct lu_env *env,
+               struct lod_object *lo, struct lu_extent *extent,
+               struct thandle *th, int pick, int write)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_layout_component *lod_comp;
+       bool layout_changed = false;
+       struct sel_data sd = { 0 };
+       int start_index;
+       int i = 0;
+       int max_comp = 0;
+       int rc = 0, rc2;
+       int change = 0;
+       ENTRY;
+
+       /* This makes us work on the components of the chosen mirror */
+       start_index = lo->ldo_mirrors[pick].lme_start;
+       max_comp = lo->ldo_mirrors[pick].lme_end + 1;
+       if (lo->ldo_flr_state == LCM_FL_NONE)
+               LASSERT(start_index == 0 && max_comp == lo->ldo_comp_cnt);
+
+       CDEBUG(D_LAYOUT, "extent->e_start %llu, extent->e_end %llu\n",
+              extent->e_start, extent->e_end);
+       for (i = start_index; i < max_comp; i++) {
+               lod_comp = &lo->ldo_comp_entries[i];
+
+               /* We've passed all components of interest */
+               if (lod_comp->llc_extent.e_start >= extent->e_end)
+                       break;
+
+               if (lod_comp->llc_flags & LCME_FL_EXTENSION) {
+                       layout_changed = true;
+                       rc = lod_sel_handler(env, lo, extent, th, &max_comp,
+                                            i, write, &sd);
+                       if (rc < 0)
+                               GOTO(out, rc);
+
+                       /* Nothing has changed behind the prev one */
+                       i -= 2;
+                       continue;
+               }
+       }
+
+       /* We may have added or removed components.  If so, we must update the
+        * start & ends of all the mirrors after the current one, and the end
+        * of the current mirror. */
+       change = max_comp - 1 - lo->ldo_mirrors[pick].lme_end;
+       if (change) {
+               lo->ldo_mirrors[pick].lme_end += change;
+               for (i = pick + 1; i < lo->ldo_mirror_count; i++) {
+                       lo->ldo_mirrors[i].lme_start += change;
+                       lo->ldo_mirrors[i].lme_end += change;
+               }
+       }
+
+       EXIT;
+out:
+       /* The amount of components has changed, adjust the lti_comp_idx */
+       rc2 = lod_layout_data_init(info, lo->ldo_comp_cnt);
+
+       return rc < 0 ? rc : rc2 < 0 ? rc2 : layout_changed;
+}
+
+/* If striping is already instantiated or INIT'ed DOM? */
+static bool lod_is_instantiation_needed(struct lod_layout_component *comp)
+{
+       return !(((lov_pattern(comp->llc_pattern) == LOV_PATTERN_MDT) &&
+                 lod_comp_inited(comp)) || comp->llc_stripe);
+}
+
+/**
+ * Declare layout update for a non-FLR layout.
+ *
+ * \param[in] env      execution environment for this thread
+ * \param[in,out] lo   object to update the layout of
+ * \param[in] layout   layout intent for requested operation, "update" is
+ *                     a process of reacting to this
+ * \param[in] buf      buffer containing lov ea (see comment on usage inline)
+ * \param[in] th       transaction handle for this operation
+ *
+ * \retval     0 on success
+ * \retval     negative errno on error
+ */
+static int lod_declare_update_plain(const struct lu_env *env,
+               struct lod_object *lo, struct layout_intent *layout,
+               const struct lu_buf *buf, struct thandle *th)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_device *d = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+       struct lod_layout_component *lod_comp;
+       struct lov_comp_md_v1 *comp_v1 = NULL;
+       bool layout_changed = false;
+       bool replay = false;
+       int i, rc;
+       ENTRY;
+
+       LASSERT(lo->ldo_flr_state == LCM_FL_NONE);
+
+       /*
+        * In case the client is passing lovea, which only happens during
+        * the replay of layout intent write RPC for now, we may need to
+        * parse the lovea and apply new layout configuration.
+        */
+       if (buf && buf->lb_len)  {
+               struct lov_user_md_v1 *v1 = buf->lb_buf;
+
+               if (v1->lmm_magic != (LOV_MAGIC_DEFINED | LOV_MAGIC_COMP_V1) &&
+                   v1->lmm_magic != __swab32(LOV_MAGIC_DEFINED |
+                                             LOV_MAGIC_COMP_V1)) {
+                       CERROR("%s: the replay buffer of layout extend "
+                              "(magic %#x) does not contain expected "
+                              "composite layout.\n",
+                              lod2obd(d)->obd_name, v1->lmm_magic);
+                       GOTO(out, rc = -EINVAL);
+               }
+
+               rc = lod_use_defined_striping(env, lo, buf);
+               if (rc)
+                       GOTO(out, rc);
+               lo->ldo_comp_cached = 1;
+
+               rc = lod_get_lov_ea(env, lo);
+               if (rc <= 0)
+                       GOTO(out, rc);
+               /* old on-disk EA is stored in info->lti_buf */
+               comp_v1 = (struct lov_comp_md_v1 *)info->lti_buf.lb_buf;
+               replay = true;
+               layout_changed = true;
+
+               rc = lod_layout_data_init(info, lo->ldo_comp_cnt);
+               if (rc)
+                       GOTO(out, rc);
+       } else {
+               /* non replay path */
+               rc = lod_striping_load(env, lo);
+               if (rc)
+                       GOTO(out, rc);
+       }
+
+       /* Make sure defined layout covers the requested write range. */
+       lod_comp = &lo->ldo_comp_entries[lo->ldo_comp_cnt - 1];
+       if (lo->ldo_comp_cnt > 1 &&
+           lod_comp->llc_extent.e_end != OBD_OBJECT_EOF &&
+           lod_comp->llc_extent.e_end < layout->li_extent.e_end) {
+               CDEBUG_LIMIT(replay ? D_ERROR : D_LAYOUT,
+                            "%s: the defined layout [0, %#llx) does not "
+                            "covers the write range "DEXT"\n",
+                            lod2obd(d)->obd_name, lod_comp->llc_extent.e_end,
+                            PEXT(&layout->li_extent));
+               GOTO(out, rc = -EINVAL);
+       }
+
+       CDEBUG(D_LAYOUT, "%s: "DFID": update components "DEXT"\n",
+              lod2obd(d)->obd_name, PFID(lod_object_fid(lo)),
+              PEXT(&layout->li_extent));
+
+       if (!replay) {
+               rc = lod_declare_update_extents(env, lo, &layout->li_extent,
+                               th, 0, layout->li_opc == LAYOUT_INTENT_WRITE);
+               if (rc < 0)
+                       GOTO(out, rc);
+               else if (rc)
+                       layout_changed = true;
+       }
+
+       /*
+        * Iterate ld->ldo_comp_entries, find the component whose extent under
+        * the write range and not instantianted.
+        */
+       for (i = 0; i < lo->ldo_comp_cnt; i++) {
+               lod_comp = &lo->ldo_comp_entries[i];
+
+               if (lod_comp->llc_extent.e_start >= layout->li_extent.e_end)
+                       break;
+
+               if (!replay) {
+                       /* If striping is instantiated or INIT'ed DOM skip */
+                       if (!lod_is_instantiation_needed(lod_comp))
+                               continue;
+               } else {
+                       /**
+                        * In replay path, lod_comp is the EA passed by
+                        * client replay buffer,  comp_v1 is the pre-recovery
+                        * on-disk EA, we'd sift out those components which
+                        * were init-ed in the on-disk EA.
+                        */
+                       if (le32_to_cpu(comp_v1->lcm_entries[i].lcme_flags) &
+                           LCME_FL_INIT)
+                               continue;
+               }
+               /*
+                * this component hasn't instantiated in normal path, or during
+                * replay it needs replay the instantiation.
+                */
+
+               /* A released component is being extended */
+               if (lod_comp->llc_pattern & LOV_PATTERN_F_RELEASED)
+                       GOTO(out, rc = -EINVAL);
+
+               LASSERT(info->lti_comp_idx != NULL);
+               info->lti_comp_idx[info->lti_count++] = i;
+               layout_changed = true;
+       }
+
+       if (!layout_changed)
+               RETURN(-EALREADY);
 
        lod_obj_inc_layout_gen(lo);
-       rc = lod_declare_instantiate_components(env, lo, th);
+       rc = lod_declare_instantiate_components(env, lo, th, 0);
+       EXIT;
 out:
        if (rc)
                lod_striping_free(env, lo);
-       RETURN(rc);
+       return rc;
 }
 
 static inline int lod_comp_index(struct lod_object *lo,
@@ -5909,15 +7606,21 @@ static inline int lod_comp_index(struct lod_object *lo,
 /**
  * Stale other mirrors by writing extent.
  */
-static void lod_stale_components(struct lod_object *lo, int primary,
-                                struct lu_extent *extent)
+static int lod_stale_components(const struct lu_env *env, struct lod_object *lo,
+                               int primary, struct lu_extent *extent,
+                               struct thandle *th)
 {
        struct lod_layout_component *pri_comp, *lod_comp;
+       struct lu_extent pri_extent;
+       int rc = 0;
        int i;
+       ENTRY;
 
        /* The writing extent decides which components in the primary
         * are affected... */
        CDEBUG(D_LAYOUT, "primary mirror %d, "DEXT"\n", primary, PEXT(extent));
+
+restart:
        lod_foreach_mirror_comp(pri_comp, lo, primary) {
                if (!lu_extent_is_overlapped(extent, &pri_comp->llc_extent))
                        continue;
@@ -5926,15 +7629,27 @@ static void lod_stale_components(struct lod_object *lo, int primary,
                       lod_comp_index(lo, pri_comp),
                       PEXT(&pri_comp->llc_extent));
 
+               pri_extent.e_start = pri_comp->llc_extent.e_start;
+               pri_extent.e_end = pri_comp->llc_extent.e_end;
+
                for (i = 0; i < lo->ldo_mirror_count; i++) {
                        if (i == primary)
                                continue;
+                       rc = lod_declare_update_extents(env, lo, &pri_extent,
+                                                       th, i, 0);
+                       /* if update_extents changed the layout, it may have
+                        * reallocated the component array, so start over to
+                        * avoid using stale pointers */
+                       if (rc == 1)
+                               goto restart;
+                       if (rc < 0)
+                               RETURN(rc);
 
                        /* ... and then stale other components that are
                         * overlapping with primary components */
                        lod_foreach_mirror_comp(lod_comp, lo, i) {
                                if (!lu_extent_is_overlapped(
-                                                       &pri_comp->llc_extent,
+                                                       &pri_extent,
                                                        &lod_comp->llc_extent))
                                        continue;
 
@@ -5946,6 +7661,8 @@ static void lod_stale_components(struct lod_object *lo, int primary,
                        }
                }
        }
+
+       RETURN(rc);
 }
 
 /**
@@ -5979,8 +7696,8 @@ static inline int lod_check_ost_avail(const struct lu_env *env,
 
        ost = OST_TGT(lod, idx);
        if (ost->ltd_statfs.os_state &
-               (OS_STATE_READONLY | OS_STATE_ENOSPC | OS_STATE_ENOINO |
-                OS_STATE_NOPRECREATE) ||
+               (OS_STATFS_READONLY | OS_STATFS_ENOSPC | OS_STATFS_ENOINO |
+                OS_STATFS_NOPRECREATE) ||
            ost->ltd_active == 0) {
                CDEBUG(D_LAYOUT, DFID ": mirror %d OST%d unavail, rc = %d\n",
                       PFID(lod_object_fid(lo)), index, idx, rc);
@@ -6017,7 +7734,12 @@ static int lod_primary_pick(const struct lu_env *env, struct lod_object *lo,
         * This algo can be revised later after knowing the topology of
         * cluster.
         */
-       lod_qos_statfs_update(env, lod);
+       lod_qos_statfs_update(env, lod, &lod->lod_ost_descs);
+
+       rc = lod_fill_mirrors(lo);
+       if (rc)
+               RETURN(rc);
+
        for (i = 0; i < lo->ldo_mirror_count; i++) {
                bool ost_avail = true;
                int index = (i + seq) % lo->ldo_mirror_count;
@@ -6029,7 +7751,7 @@ static int lod_primary_pick(const struct lu_env *env, struct lod_object *lo,
                }
 
                /* 2nd pick is for the primary mirror containing unavail OST */
-               if (lo->ldo_mirrors[index].lme_primary && second_pick < 0)
+               if (lo->ldo_mirrors[index].lme_prefer && second_pick < 0)
                        second_pick = index;
 
                /* 3rd pick is for non-primary mirror containing unavail OST */
@@ -6040,7 +7762,7 @@ static int lod_primary_pick(const struct lu_env *env, struct lod_object *lo,
                 * we found a non-primary 1st pick, we'd like to find a
                 * potential pirmary mirror.
                 */
-               if (picked >= 0 && !lo->ldo_mirrors[index].lme_primary)
+               if (picked >= 0 && !lo->ldo_mirrors[index].lme_prefer)
                        continue;
 
                /* check the availability of OSTs */
@@ -6077,7 +7799,7 @@ static int lod_primary_pick(const struct lu_env *env, struct lod_object *lo,
                 * primary with all OSTs are available, this is the perfect
                 * 1st pick.
                 */
-               if (lo->ldo_mirrors[index].lme_primary)
+               if (lo->ldo_mirrors[index].lme_prefer)
                        break;
        } /* for all mirrors */
 
@@ -6092,25 +7814,53 @@ static int lod_primary_pick(const struct lu_env *env, struct lod_object *lo,
        RETURN(picked);
 }
 
-/**
- * figure out the components should be instantiated for resync.
- */
-static int lod_prepare_resync(const struct lu_env *env, struct lod_object *lo,
-                             struct lu_extent *extent)
+static int lod_prepare_resync_mirror(const struct lu_env *env,
+                                    struct lod_object *lo,
+                                    __u16 mirror_id)
 {
        struct lod_thread_info *info = lod_env_info(env);
        struct lod_layout_component *lod_comp;
-       unsigned int need_sync = 0;
+       bool neg = !!(MIRROR_ID_NEG & mirror_id);
        int i;
 
-       CDEBUG(D_LAYOUT,
-              DFID": instantiate all stale components in "DEXT"\n",
-              PFID(lod_object_fid(lo)), PEXT(extent));
+       mirror_id &= ~MIRROR_ID_NEG;
 
-       /**
-        * instantiate all components within this extent, even non-stale
-        * components.
-        */
+       for (i = 0; i < lo->ldo_mirror_count; i++) {
+               if ((!neg && lo->ldo_mirrors[i].lme_id != mirror_id) ||
+                   (neg && lo->ldo_mirrors[i].lme_id == mirror_id))
+                       continue;
+
+               lod_foreach_mirror_comp(lod_comp, lo, i) {
+                       if (lod_comp_inited(lod_comp))
+                               continue;
+
+                       info->lti_comp_idx[info->lti_count++] =
+                               lod_comp_index(lo, lod_comp);
+               }
+       }
+
+       return 0;
+}
+
+/**
+ * figure out the components should be instantiated for resync.
+ */
+static int lod_prepare_resync(const struct lu_env *env, struct lod_object *lo,
+                             struct lu_extent *extent)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_layout_component *lod_comp;
+       unsigned int need_sync = 0;
+       int i;
+
+       CDEBUG(D_LAYOUT,
+              DFID": instantiate all stale components in "DEXT"\n",
+              PFID(lod_object_fid(lo)), PEXT(extent));
+
+       /**
+        * instantiate all components within this extent, even non-stale
+        * components.
+        */
        for (i = 0; i < lo->ldo_mirror_count; i++) {
                if (!lo->ldo_mirrors[i].lme_stale)
                        continue;
@@ -6153,6 +7903,7 @@ static int lod_declare_update_rdonly(const struct lu_env *env,
 
        if (mlc->mlc_opc == MD_LAYOUT_WRITE) {
                struct layout_intent *layout = mlc->mlc_intent;
+               int write = layout->li_opc == LAYOUT_INTENT_WRITE;
                int picked;
 
                extent = layout->li_extent;
@@ -6167,6 +7918,12 @@ static int lod_declare_update_rdonly(const struct lu_env *env,
                       PFID(lod_object_fid(lo)),
                       lo->ldo_mirrors[picked].lme_id);
 
+               /* Update extents of primary before staling */
+               rc = lod_declare_update_extents(env, lo, &extent, th, picked,
+                                               write);
+               if (rc < 0)
+                       GOTO(out, rc);
+
                if (layout->li_opc == LAYOUT_INTENT_TRUNC) {
                        /**
                         * trunc transfers [0, size) in the intent extent, we'd
@@ -6177,7 +7934,9 @@ static int lod_declare_update_rdonly(const struct lu_env *env,
                }
 
                /* stale overlapping components from other mirrors */
-               lod_stale_components(lo, picked, &extent);
+               rc = lod_stale_components(env, lo, picked, &extent, th);
+               if (rc < 0)
+                       GOTO(out, rc);
 
                /* restore truncate intent extent */
                if (layout->li_opc == LAYOUT_INTENT_TRUNC)
@@ -6191,7 +7950,7 @@ static int lod_declare_update_rdonly(const struct lu_env *env,
                                                     &lod_comp->llc_extent))
                                break;
 
-                       if (lod_comp_inited(lod_comp))
+                       if (!lod_is_instantiation_needed(lod_comp))
                                continue;
 
                        info->lti_comp_idx[info->lti_count++] =
@@ -6207,23 +7966,33 @@ static int lod_declare_update_rdonly(const struct lu_env *env,
                 * prep uninited all components assuming any non-stale mirror
                 * could be picked as the primary mirror.
                 */
-               for (i = 0; i < lo->ldo_mirror_count; i++) {
-                       if (lo->ldo_mirrors[i].lme_stale)
-                               continue;
+               if (mlc->mlc_mirror_id == 0) {
+                       /* normal resync */
+                       for (i = 0; i < lo->ldo_mirror_count; i++) {
+                               if (lo->ldo_mirrors[i].lme_stale)
+                                       continue;
 
-                       lod_foreach_mirror_comp(lod_comp, lo, i) {
-                               if (!lod_comp_inited(lod_comp))
-                                       break;
+                               lod_foreach_mirror_comp(lod_comp, lo, i) {
+                                       if (!lod_comp_inited(lod_comp))
+                                               break;
 
-                               if (extent.e_end < lod_comp->llc_extent.e_end)
-                                       extent.e_end =
-                                               lod_comp->llc_extent.e_end;
+                                       if (extent.e_end <
+                                               lod_comp->llc_extent.e_end)
+                                               extent.e_end =
+                                                    lod_comp->llc_extent.e_end;
+                               }
                        }
+                       rc = lod_prepare_resync(env, lo, &extent);
+                       if (rc)
+                               GOTO(out, rc);
+               } else {
+                       /* mirror write, try to init its all components */
+                       rc = lod_prepare_resync_mirror(env, lo,
+                                                      mlc->mlc_mirror_id);
+                       if (rc)
+                               GOTO(out, rc);
                }
 
-               rc = lod_prepare_resync(env, lo, &extent);
-               if (rc)
-                       GOTO(out, rc);
                /* change the file state to SYNC_PENDING */
                lo->ldo_flr_state = LCM_FL_SYNC_PENDING;
        }
@@ -6235,11 +8004,11 @@ static int lod_declare_update_rdonly(const struct lu_env *env,
        if (lo->ldo_layout_gen > (LCME_ID_MAX >> 1)) {
                __u32 layout_version;
 
-               cfs_get_random_bytes(&layout_version, sizeof(layout_version));
+               get_random_bytes(&layout_version, sizeof(layout_version));
                lo->ldo_layout_gen = layout_version & 0xffff;
        }
 
-       rc = lod_declare_instantiate_components(env, lo, th);
+       rc = lod_declare_instantiate_components(env, lo, th, 0);
        if (rc)
                GOTO(out, rc);
 
@@ -6274,205 +8043,846 @@ static int lod_declare_update_write_pending(const struct lu_env *env,
        LASSERT(mlc->mlc_opc == MD_LAYOUT_WRITE ||
                mlc->mlc_opc == MD_LAYOUT_RESYNC);
 
-       /* look for the primary mirror */
-       for (i = 0; i < lo->ldo_mirror_count; i++) {
-               if (lo->ldo_mirrors[i].lme_stale)
-                       continue;
+       /* look for the first preferred mirror */
+       for (i = 0; i < lo->ldo_mirror_count; i++) {
+               if (lo->ldo_mirrors[i].lme_stale)
+                       continue;
+               if (lo->ldo_mirrors[i].lme_prefer == 0)
+                       continue;
+
+               primary = i;
+               break;
+       }
+       if (primary < 0) {
+               /* no primary, use any in-sync */
+               for (i = 0; i < lo->ldo_mirror_count; i++) {
+                       if (lo->ldo_mirrors[i].lme_stale)
+                               continue;
+                       primary = i;
+                       break;
+               }
+               if (primary < 0) {
+                       CERROR(DFID ": doesn't have a primary mirror\n",
+                              PFID(lod_object_fid(lo)));
+                       GOTO(out, rc = -ENODATA);
+               }
+       }
+
+       CDEBUG(D_LAYOUT, DFID": found primary %u\n",
+              PFID(lod_object_fid(lo)), lo->ldo_mirrors[primary].lme_id);
+
+       LASSERT(!lo->ldo_mirrors[primary].lme_stale);
+
+       /* for LAYOUT_WRITE opc, it has to do the following operations:
+        * 1. stale overlapping componets from stale mirrors;
+        * 2. instantiate components of the primary mirror;
+        * 3. transfter layout version to all objects of the primary;
+        *
+        * for LAYOUT_RESYNC opc, it will do:
+        * 1. instantiate components of all stale mirrors;
+        * 2. transfer layout version to all objects to close write era. */
+
+       if (mlc->mlc_opc == MD_LAYOUT_WRITE) {
+               struct layout_intent *layout = mlc->mlc_intent;
+               int write = layout->li_opc == LAYOUT_INTENT_WRITE;
+
+               LASSERT(mlc->mlc_intent != NULL);
+
+               extent = mlc->mlc_intent->li_extent;
+
+               CDEBUG(D_LAYOUT, DFID": intent to write: "DEXT"\n",
+                      PFID(lod_object_fid(lo)), PEXT(&extent));
+
+               /* 1. Update extents of primary before staling */
+               rc = lod_declare_update_extents(env, lo, &extent, th, primary,
+                                               write);
+               if (rc < 0)
+                       GOTO(out, rc);
+
+               if (mlc->mlc_intent->li_opc == LAYOUT_INTENT_TRUNC) {
+                       /**
+                        * trunc transfers [0, size) in the intent extent, we'd
+                        * stale components overlapping [size, eof).
+                        */
+                       extent.e_start = extent.e_end;
+                       extent.e_end = OBD_OBJECT_EOF;
+               }
+
+               /* 2. stale overlapping components */
+               rc = lod_stale_components(env, lo, primary, &extent, th);
+               if (rc < 0)
+                       GOTO(out, rc);
+
+               /* 3. find the components which need instantiating.
+                * instantiate [0, mlc->mlc_intent->e_end) */
+
+               /* restore truncate intent extent */
+               if (mlc->mlc_intent->li_opc == LAYOUT_INTENT_TRUNC)
+                       extent.e_end = extent.e_start;
+               extent.e_start = 0;
+
+               lod_foreach_mirror_comp(lod_comp, lo, primary) {
+                       if (!lu_extent_is_overlapped(&extent,
+                                                    &lod_comp->llc_extent))
+                               break;
+
+                       if (!lod_is_instantiation_needed(lod_comp))
+                               continue;
+
+                       CDEBUG(D_LAYOUT, "write instantiate %d / %d\n",
+                              primary, lod_comp_index(lo, lod_comp));
+                       info->lti_comp_idx[info->lti_count++] =
+                                               lod_comp_index(lo, lod_comp);
+               }
+       } else { /* MD_LAYOUT_RESYNC */
+               if (mlc->mlc_mirror_id == 0) {
+                       /* normal resync */
+                       lod_foreach_mirror_comp(lod_comp, lo, primary) {
+                               if (!lod_comp_inited(lod_comp))
+                                       break;
+
+                               extent.e_end = lod_comp->llc_extent.e_end;
+                       }
+
+                       rc = lod_prepare_resync(env, lo, &extent);
+                       if (rc)
+                               GOTO(out, rc);
+               } else {
+                       /* mirror write, try to init its all components */
+                       rc = lod_prepare_resync_mirror(env, lo,
+                                                      mlc->mlc_mirror_id);
+                       if (rc)
+                               GOTO(out, rc);
+               }
+
+               /* change the file state to SYNC_PENDING */
+               lo->ldo_flr_state = LCM_FL_SYNC_PENDING;
+       }
+
+       rc = lod_declare_instantiate_components(env, lo, th, 0);
+       if (rc)
+               GOTO(out, rc);
+
+       /* 3. transfer layout version to OST objects.
+        * transfer new layout version to OST objects so that stale writes
+        * can be denied. It also ends an era of writing by setting
+        * LU_LAYOUT_RESYNC. Normal client can never use this bit to
+        * send write RPC; only resync RPCs could do it. */
+       layout_attr->la_valid = LA_LAYOUT_VERSION;
+       layout_attr->la_layout_version = 0; /* set current version */
+       if (mlc->mlc_opc == MD_LAYOUT_RESYNC)
+               layout_attr->la_layout_version = LU_LAYOUT_RESYNC;
+       rc = lod_declare_attr_set(env, &lo->ldo_obj, layout_attr, th);
+       if (rc)
+               GOTO(out, rc);
+
+       lod_obj_inc_layout_gen(lo);
+out:
+       if (rc)
+               lod_striping_free(env, lo);
+       RETURN(rc);
+}
+
+static int lod_declare_update_sync_pending(const struct lu_env *env,
+               struct lod_object *lo, struct md_layout_change *mlc,
+               struct thandle *th)
+{
+       struct lod_thread_info  *info = lod_env_info(env);
+       struct lu_attr *layout_attr = &info->lti_layout_attr;
+       unsigned sync_components = 0;
+       unsigned resync_components = 0;
+       int i;
+       int rc;
+       ENTRY;
+
+       LASSERT(lo->ldo_flr_state == LCM_FL_SYNC_PENDING);
+       LASSERT(mlc->mlc_opc == MD_LAYOUT_RESYNC_DONE ||
+               mlc->mlc_opc == MD_LAYOUT_WRITE);
+
+       CDEBUG(D_LAYOUT, DFID ": received op %d in sync pending\n",
+              PFID(lod_object_fid(lo)), mlc->mlc_opc);
+
+       if (mlc->mlc_opc == MD_LAYOUT_WRITE) {
+               CDEBUG(D_LAYOUT, DFID": cocurrent write to sync pending\n",
+                      PFID(lod_object_fid(lo)));
+
+               lo->ldo_flr_state = LCM_FL_WRITE_PENDING;
+               return lod_declare_update_write_pending(env, lo, mlc, th);
+       }
+
+       /* MD_LAYOUT_RESYNC_DONE */
+
+       for (i = 0; i < lo->ldo_comp_cnt; i++) {
+               struct lod_layout_component *lod_comp;
+               int j;
+
+               lod_comp = &lo->ldo_comp_entries[i];
+
+               if (!(lod_comp->llc_flags & LCME_FL_STALE)) {
+                       sync_components++;
+                       continue;
+               }
+
+               for (j = 0; j < mlc->mlc_resync_count; j++) {
+                       if (lod_comp->llc_id != mlc->mlc_resync_ids[j])
+                               continue;
+
+                       mlc->mlc_resync_ids[j] = LCME_ID_INVAL;
+                       lod_comp->llc_flags &= ~LCME_FL_STALE;
+                       resync_components++;
+                       break;
+               }
+       }
+
+       /* valid check */
+       for (i = 0; i < mlc->mlc_resync_count; i++) {
+               if (mlc->mlc_resync_ids[i] == LCME_ID_INVAL)
+                       continue;
+
+               CDEBUG(D_LAYOUT, DFID": lcme id %u (%d / %zd) not exist "
+                      "or already synced\n", PFID(lod_object_fid(lo)),
+                      mlc->mlc_resync_ids[i], i, mlc->mlc_resync_count);
+               GOTO(out, rc = -EINVAL);
+       }
+
+       if (!sync_components || (mlc->mlc_resync_count && !resync_components)) {
+               CDEBUG(D_LAYOUT, DFID": no mirror in sync\n",
+                      PFID(lod_object_fid(lo)));
+
+               /* tend to return an error code here to prevent
+                * the MDT from setting SoM attribute */
+               GOTO(out, rc = -EINVAL);
+       }
+
+       CDEBUG(D_LAYOUT, DFID": synced %u resynced %u/%zu components\n",
+              PFID(lod_object_fid(lo)),
+              sync_components, resync_components, mlc->mlc_resync_count);
+
+       lo->ldo_flr_state = LCM_FL_RDONLY;
+       lod_obj_inc_layout_gen(lo);
+
+       layout_attr->la_valid = LA_LAYOUT_VERSION;
+       layout_attr->la_layout_version = 0; /* set current version */
+       rc = lod_declare_attr_set(env, &lo->ldo_obj, layout_attr, th);
+       if (rc)
+               GOTO(out, rc);
+
+       info->lti_buf.lb_len = lod_comp_md_size(lo, false);
+       rc = lod_sub_declare_xattr_set(env, lod_object_child(lo),
+                                      &info->lti_buf, XATTR_NAME_LOV, 0, th);
+       EXIT;
+
+out:
+       if (rc)
+               lod_striping_free(env, lo);
+       RETURN(rc);
+}
+
+typedef int (*mlc_handler)(const struct lu_env *env, struct dt_object *dt,
+                          const struct md_layout_change *mlc,
+                          struct thandle *th);
+
+/**
+ * Attach stripes after target's for migrating directory. NB, we
+ * only need to declare this, the actual work is done inside
+ * lod_xattr_set_lmv().
+ *
+ * \param[in] env      execution environment
+ * \param[in] dt       target object
+ * \param[in] mlc      layout change data
+ * \param[in] th       transaction handle
+ *
+ * \retval             0 on success
+ * \retval             negative if failed
+ */
+static int lod_dir_declare_layout_attach(const struct lu_env *env,
+                                        struct dt_object *dt,
+                                        const struct md_layout_change *mlc,
+                                        struct thandle *th)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_device *lod = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lod_tgt_descs *ltd = &lod->lod_mdt_descs;
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next = dt_object_child(dt);
+       struct dt_object_format *dof = &info->lti_format;
+       struct lmv_mds_md_v1 *lmv = mlc->mlc_buf.lb_buf;
+       struct dt_object **stripes;
+       __u32 stripe_count = le32_to_cpu(lmv->lmv_stripe_count);
+       struct lu_fid *fid = &info->lti_fid;
+       struct lod_tgt_desc *tgt;
+       struct dt_object *dto;
+       struct dt_device *tgt_dt;
+       int type = LU_SEQ_RANGE_ANY;
+       struct dt_insert_rec *rec = &info->lti_dt_rec;
+       char *stripe_name = info->lti_key;
+       struct lu_name *sname;
+       struct linkea_data ldata = { NULL };
+       struct lu_buf linkea_buf;
+       __u32 idx;
+       int i;
+       int rc;
+
+       ENTRY;
+
+       if (!lmv_is_sane(lmv))
+               RETURN(-EINVAL);
+
+       if (!dt_try_as_dir(env, dt))
+               return -ENOTDIR;
+
+       dof->dof_type = DFT_DIR;
+
+       OBD_ALLOC_PTR_ARRAY(stripes, (lo->ldo_dir_stripe_count + stripe_count));
+       if (!stripes)
+               RETURN(-ENOMEM);
+
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++)
+               stripes[i] = lo->ldo_stripe[i];
+
+       rec->rec_type = S_IFDIR;
+
+       for (i = 0; i < stripe_count; i++) {
+               fid_le_to_cpu(fid,
+                       &lmv->lmv_stripe_fids[i]);
+               if (!fid_is_sane(fid))
+                       continue;
+
+               rc = lod_fld_lookup(env, lod, fid, &idx, &type);
+               if (rc)
+                       GOTO(out, rc);
+
+               if (idx == lod2lu_dev(lod)->ld_site->ld_seq_site->ss_node_id) {
+                       tgt_dt = lod->lod_child;
+               } else {
+                       tgt = LTD_TGT(ltd, idx);
+                       if (tgt == NULL)
+                               GOTO(out, rc = -ESTALE);
+                       tgt_dt = tgt->ltd_tgt;
+               }
+
+               dto = dt_locate_at(env, tgt_dt, fid,
+                                 lo->ldo_obj.do_lu.lo_dev->ld_site->ls_top_dev,
+                                 NULL);
+               if (IS_ERR(dto))
+                       GOTO(out, rc = PTR_ERR(dto));
+
+               stripes[i + lo->ldo_dir_stripe_count] = dto;
+
+               if (!dt_try_as_dir(env, dto))
+                       GOTO(out, rc = -ENOTDIR);
+
+               rc = lod_sub_declare_ref_add(env, dto, th);
+               if (rc)
+                       GOTO(out, rc);
+
+               rec->rec_fid = lu_object_fid(&dto->do_lu);
+               rc = lod_sub_declare_insert(env, dto,
+                                           (const struct dt_rec *)rec,
+                                           (const struct dt_key *)dot, th);
+               if (rc)
+                       GOTO(out, rc);
+
+               rc = lod_sub_declare_insert(env, dto,
+                                           (const struct dt_rec *)rec,
+                                           (const struct dt_key *)dotdot, th);
+               if (rc)
+                       GOTO(out, rc);
+
+               rc = lod_sub_declare_xattr_set(env, dto, &mlc->mlc_buf,
+                                               XATTR_NAME_LMV, 0, th);
+               if (rc)
+                       GOTO(out, rc);
+
+               snprintf(stripe_name, sizeof(info->lti_key), DFID":%u",
+                        PFID(lu_object_fid(&dto->do_lu)),
+                        i + lo->ldo_dir_stripe_count);
+
+               sname = lod_name_get(env, stripe_name, strlen(stripe_name));
+               rc = linkea_links_new(&ldata, &info->lti_linkea_buf,
+                                     sname, lu_object_fid(&dt->do_lu));
+               if (rc)
+                       GOTO(out, rc);
+
+               linkea_buf.lb_buf = ldata.ld_buf->lb_buf;
+               linkea_buf.lb_len = ldata.ld_leh->leh_len;
+               rc = lod_sub_declare_xattr_set(env, dto, &linkea_buf,
+                                              XATTR_NAME_LINK, 0, th);
+               if (rc)
+                       GOTO(out, rc);
+
+               rc = lod_sub_declare_insert(env, next,
+                                           (const struct dt_rec *)rec,
+                                           (const struct dt_key *)stripe_name,
+                                           th);
+               if (rc)
+                       GOTO(out, rc);
+
+               rc = lod_sub_declare_ref_add(env, next, th);
+               if (rc)
+                       GOTO(out, rc);
+       }
+
+       if (lo->ldo_stripe)
+               OBD_FREE_PTR_ARRAY(lo->ldo_stripe,
+                                  lo->ldo_dir_stripes_allocated);
+       lo->ldo_stripe = stripes;
+       lo->ldo_is_foreign = 0;
+       lo->ldo_dir_migrate_offset = lo->ldo_dir_stripe_count;
+       lo->ldo_dir_migrate_hash = le32_to_cpu(lmv->lmv_hash_type);
+       lo->ldo_dir_stripe_count += stripe_count;
+       lo->ldo_dir_stripes_allocated += stripe_count;
+
+       /* plain directory split creates target as a plain directory, while
+        * after source attached as the first stripe, it becomes a striped
+        * directory, set correct do_index_ops, otherwise it can't be unlinked.
+        */
+       dt->do_index_ops = &lod_striped_index_ops;
+
+       RETURN(0);
+out:
+       i = lo->ldo_dir_stripe_count;
+       while (i < lo->ldo_dir_stripe_count + stripe_count && stripes[i])
+               dt_object_put(env, stripes[i++]);
+
+       OBD_FREE_PTR_ARRAY(stripes, stripe_count + lo->ldo_dir_stripe_count);
+       return rc;
+}
+
+static int lod_dir_declare_layout_detach(const struct lu_env *env,
+                                        struct dt_object *dt,
+                                        const struct md_layout_change *unused,
+                                        struct thandle *th)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next = dt_object_child(dt);
+       char *stripe_name = info->lti_key;
+       struct dt_object *dto;
+       int i;
+       int rc = 0;
+
+       if (!dt_try_as_dir(env, dt))
+               return -ENOTDIR;
+
+       if (!lo->ldo_dir_stripe_count)
+               return lod_sub_declare_delete(env, next,
+                                       (const struct dt_key *)dotdot, th);
+
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               dto = lo->ldo_stripe[i];
+               if (!dto)
+                       continue;
+
+               if (!dt_try_as_dir(env, dto))
+                       return -ENOTDIR;
+
+               rc = lod_sub_declare_delete(env, dto,
+                                       (const struct dt_key *)dotdot, th);
+               if (rc)
+                       return rc;
+
+               snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
+                        PFID(lu_object_fid(&dto->do_lu)), i);
+
+               rc = lod_sub_declare_delete(env, next,
+                                       (const struct dt_key *)stripe_name, th);
+               if (rc)
+                       return rc;
+
+               rc = lod_sub_declare_ref_del(env, next, th);
+               if (rc)
+                       return rc;
+       }
+
+       return 0;
+}
+
+static int dt_dir_is_empty(const struct lu_env *env,
+                          struct dt_object *obj)
+{
+       struct dt_it *it;
+       const struct dt_it_ops *iops;
+       int rc;
+
+       ENTRY;
+
+       if (!dt_try_as_dir(env, obj))
+               RETURN(-ENOTDIR);
+
+       iops = &obj->do_index_ops->dio_it;
+       it = iops->init(env, obj, LUDA_64BITHASH);
+       if (IS_ERR(it))
+               RETURN(PTR_ERR(it));
+
+       rc = iops->get(env, it, (const struct dt_key *)"");
+       if (rc > 0) {
+               int i;
+
+               for (rc = 0, i = 0; rc == 0 && i < 3; ++i)
+                       rc = iops->next(env, it);
+               if (!rc)
+                       rc = -ENOTEMPTY;
+               else if (rc == 1)
+                       rc = 0;
+       } else if (!rc) {
+               /* Huh? Index contains no zero key? */
+               rc = -EIO;
+       }
+
+       iops->put(env, it);
+       iops->fini(env, it);
+
+       RETURN(rc);
+}
+
+static int lod_dir_declare_layout_shrink(const struct lu_env *env,
+                                        struct dt_object *dt,
+                                        const struct md_layout_change *mlc,
+                                        struct thandle *th)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next = dt_object_child(dt);
+       struct lmv_user_md *lmu = mlc->mlc_buf.lb_buf;
+       char *stripe_name = info->lti_key;
+       struct lu_buf *lmv_buf = &info->lti_buf;
+       __u32 final_stripe_count;
+       struct dt_object *dto;
+       int i;
+       int rc;
+
+       LASSERT(lmu);
+
+       if (!dt_try_as_dir(env, dt))
+               return -ENOTDIR;
+
+       /* shouldn't be called on plain directory */
+       LASSERT(lo->ldo_dir_stripe_count);
+
+       lmv_buf->lb_buf = &info->lti_lmv.lmv_md_v1;
+       lmv_buf->lb_len = sizeof(info->lti_lmv.lmv_md_v1);
+
+       final_stripe_count = le32_to_cpu(lmu->lum_stripe_count);
+       LASSERT(final_stripe_count &&
+               final_stripe_count < lo->ldo_dir_stripe_count);
+
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               dto = lo->ldo_stripe[i];
+               if (!dto)
+                       continue;
+
+               if (i < final_stripe_count) {
+                       rc = lod_sub_declare_xattr_set(env, dto, lmv_buf,
+                                                      XATTR_NAME_LMV,
+                                                      LU_XATTR_REPLACE, th);
+                       if (rc)
+                               return rc;
+
+                       continue;
+               }
+
+               rc = dt_dir_is_empty(env, dto);
+               if (rc < 0)
+                       return rc;
+
+               rc = lod_sub_declare_ref_del(env, dto, th);
+               if (rc)
+                       return rc;
+
+               rc = lod_sub_declare_destroy(env, dto, th);
+               if (rc)
+                       return rc;
+
+               snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
+                        PFID(lu_object_fid(&dto->do_lu)), i);
+
+               rc = lod_sub_declare_delete(env, next,
+                                       (const struct dt_key *)stripe_name, th);
+               if (rc)
+                       return rc;
+
+               rc = lod_sub_declare_ref_del(env, next, th);
+               if (rc)
+                       return rc;
+       }
+
+       rc = lod_sub_declare_xattr_set(env, next, lmv_buf, XATTR_NAME_LMV,
+                                      LU_XATTR_REPLACE, th);
+       return rc;
+}
+
+/**
+ * Allocate stripes for split directory.
+ *
+ * \param[in] env      execution environment
+ * \param[in] dt       target object
+ * \param[in] mlc      layout change data
+ * \param[in] th       transaction handle
+ *
+ * \retval             0 on success
+ * \retval             negative if failed
+ */
+static int lod_dir_declare_layout_split(const struct lu_env *env,
+                                       struct dt_object *dt,
+                                       const struct md_layout_change *mlc,
+                                       struct thandle *th)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_device *lod = lu2lod_dev(dt->do_lu.lo_dev);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object_format *dof = &info->lti_format;
+       struct lmv_user_md_v1 *lum = mlc->mlc_spec->u.sp_ea.eadata;
+       struct dt_object **stripes;
+       u32 stripe_count;
+       u32 saved_count;
+       int i;
+       int rc;
+
+       ENTRY;
+
+       LASSERT(le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC);
+       LASSERT(le32_to_cpu(lum->lum_stripe_offset) == LMV_OFFSET_DEFAULT);
 
-               LASSERTF(primary < 0, DFID " has multiple primary: %u / %u",
-                        PFID(lod_object_fid(lo)),
-                        lo->ldo_mirrors[i].lme_id,
-                        lo->ldo_mirrors[primary].lme_id);
+       saved_count = lo->ldo_dir_stripes_allocated;
+       stripe_count = le32_to_cpu(lum->lum_stripe_count);
+       if (stripe_count <= saved_count)
+               RETURN(-EINVAL);
 
-               primary = i;
-       }
-       if (primary < 0) {
-               CERROR(DFID ": doesn't have a primary mirror\n",
-                      PFID(lod_object_fid(lo)));
-               GOTO(out, rc = -ENODATA);
-       }
+       dof->dof_type = DFT_DIR;
 
-       CDEBUG(D_LAYOUT, DFID": found primary %u\n",
-              PFID(lod_object_fid(lo)), lo->ldo_mirrors[primary].lme_id);
+       OBD_ALLOC(stripes, sizeof(*stripes) * stripe_count);
+       if (!stripes)
+               RETURN(-ENOMEM);
 
-       LASSERT(!lo->ldo_mirrors[primary].lme_stale);
+       for (i = 0; i < lo->ldo_dir_stripes_allocated; i++)
+               stripes[i] = lo->ldo_stripe[i];
 
-       /* for LAYOUT_WRITE opc, it has to do the following operations:
-        * 1. stale overlapping componets from stale mirrors;
-        * 2. instantiate components of the primary mirror;
-        * 3. transfter layout version to all objects of the primary;
-        *
-        * for LAYOUT_RESYNC opc, it will do:
-        * 1. instantiate components of all stale mirrors;
-        * 2. transfer layout version to all objects to close write era. */
+       lod_qos_statfs_update(env, lod, &lod->lod_mdt_descs);
+       rc = lod_mdt_alloc_qos(env, lo, stripes, saved_count, stripe_count);
+       if (rc == -EAGAIN)
+               rc = lod_mdt_alloc_rr(env, lo, stripes, saved_count,
+                                     stripe_count);
+       if (rc < 0) {
+               OBD_FREE(stripes, sizeof(*stripes) * stripe_count);
+               RETURN(rc);
+       }
 
-       if (mlc->mlc_opc == MD_LAYOUT_WRITE) {
-               LASSERT(mlc->mlc_intent != NULL);
+       LASSERT(rc > saved_count);
+       OBD_FREE(lo->ldo_stripe,
+                sizeof(*stripes) * lo->ldo_dir_stripes_allocated);
+       lo->ldo_stripe = stripes;
+       lo->ldo_is_foreign = 0;
+       lo->ldo_dir_striped = 1;
+       lo->ldo_dir_stripe_count = rc;
+       lo->ldo_dir_stripes_allocated = stripe_count;
+       lo->ldo_dir_split_hash = lo->ldo_dir_hash_type;
+       lo->ldo_dir_hash_type = le32_to_cpu(lum->lum_hash_type);
+       if (!lmv_is_known_hash_type(lo->ldo_dir_hash_type))
+               lo->ldo_dir_hash_type =
+                       lod->lod_mdt_descs.ltd_lmv_desc.ld_pattern;
+       lo->ldo_dir_hash_type |= LMV_HASH_FLAG_SPLIT | LMV_HASH_FLAG_MIGRATION;
+       lo->ldo_dir_split_offset = saved_count;
+       lo->ldo_dir_layout_version++;
+       lo->ldo_dir_stripe_loaded = 1;
 
-               extent = mlc->mlc_intent->li_extent;
+       rc = lod_dir_declare_create_stripes(env, dt, mlc->mlc_attr, dof, th);
+       if (rc)
+               lod_striping_free(env, lo);
 
-               CDEBUG(D_LAYOUT, DFID": intent to write: "DEXT"\n",
-                      PFID(lod_object_fid(lo)), PEXT(&extent));
+       RETURN(rc);
+}
 
-               if (mlc->mlc_intent->li_opc == LAYOUT_INTENT_TRUNC) {
-                       /**
-                        * trunc transfers [0, size) in the intent extent, we'd
-                        * stale components overlapping [size, eof).
-                        */
-                       extent.e_start = extent.e_end;
-                       extent.e_end = OBD_OBJECT_EOF;
-               }
-               /* 1. stale overlapping components */
-               lod_stale_components(lo, primary, &extent);
+/*
+ * detach all stripes from dir master object, NB, stripes are not destroyed, but
+ * deleted from it's parent namespace, this function is called in two places:
+ * 1. mdd_migrate_mdt() detach stripes from source, and attach them to
+ *    target.
+ * 2. mdd_dir_layout_update() detach stripe before turning 1-stripe directory to
+ *    a plain directory.
+ *
+ * \param[in] env      execution environment
+ * \param[in] dt       target object
+ * \param[in] mlc      layout change data
+ * \param[in] th       transaction handle
+ *
+ * \retval             0 on success
+ * \retval             negative if failed
+ */
+static int lod_dir_layout_detach(const struct lu_env *env,
+                                struct dt_object *dt,
+                                const struct md_layout_change *mlc,
+                                struct thandle *th)
+{
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct dt_object *next = dt_object_child(dt);
+       char *stripe_name = info->lti_key;
+       struct dt_object *dto;
+       int i;
+       int rc = 0;
 
-               /* 2. find out the components need instantiating.
-                * instantiate [0, mlc->mlc_intent->e_end) */
+       ENTRY;
 
-               /* restore truncate intent extent */
-               if (mlc->mlc_intent->li_opc == LAYOUT_INTENT_TRUNC)
-                       extent.e_end = extent.e_start;
-               extent.e_start = 0;
+       if (!lo->ldo_dir_stripe_count) {
+               /* plain directory delete .. */
+               rc = lod_sub_delete(env, next,
+                                   (const struct dt_key *)dotdot, th);
+               RETURN(rc);
+       }
 
-               lod_foreach_mirror_comp(lod_comp, lo, primary) {
-                       if (!lu_extent_is_overlapped(&extent,
-                                                    &lod_comp->llc_extent))
-                               break;
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               dto = lo->ldo_stripe[i];
+               if (!dto)
+                       continue;
 
-                       if (lod_comp_inited(lod_comp))
-                               continue;
+               rc = lod_sub_delete(env, dto,
+                                   (const struct dt_key *)dotdot, th);
+               if (rc)
+                       break;
 
-                       CDEBUG(D_LAYOUT, "write instantiate %d / %d\n",
-                              primary, lod_comp_index(lo, lod_comp));
-                       info->lti_comp_idx[info->lti_count++] =
-                                               lod_comp_index(lo, lod_comp);
-               }
-       } else { /* MD_LAYOUT_RESYNC */
-               lod_foreach_mirror_comp(lod_comp, lo, primary) {
-                       if (!lod_comp_inited(lod_comp))
-                               break;
+               snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
+                        PFID(lu_object_fid(&dto->do_lu)), i);
 
-                       extent.e_end = lod_comp->llc_extent.e_end;
-               }
+               rc = lod_sub_delete(env, next,
+                                   (const struct dt_key *)stripe_name, th);
+               if (rc)
+                       break;
 
-               rc = lod_prepare_resync(env, lo, &extent);
+               rc = lod_sub_ref_del(env, next, th);
                if (rc)
-                       GOTO(out, rc);
-               /* change the file state to SYNC_PENDING */
-               lo->ldo_flr_state = LCM_FL_SYNC_PENDING;
+                       break;
        }
 
-       rc = lod_declare_instantiate_components(env, lo, th);
-       if (rc)
-               GOTO(out, rc);
-
-       /* 3. transfer layout version to OST objects.
-        * transfer new layout version to OST objects so that stale writes
-        * can be denied. It also ends an era of writing by setting
-        * LU_LAYOUT_RESYNC. Normal client can never use this bit to
-        * send write RPC; only resync RPCs could do it. */
-       layout_attr->la_valid = LA_LAYOUT_VERSION;
-       layout_attr->la_layout_version = 0; /* set current version */
-       if (mlc->mlc_opc == MD_LAYOUT_RESYNC)
-               layout_attr->la_layout_version = LU_LAYOUT_RESYNC;
-       rc = lod_declare_attr_set(env, &lo->ldo_obj, layout_attr, th);
-       if (rc)
-               GOTO(out, rc);
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               dto = lo->ldo_stripe[i];
+               if (dto)
+                       dt_object_put(env, dto);
+       }
+       OBD_FREE_PTR_ARRAY(lo->ldo_stripe, lo->ldo_dir_stripes_allocated);
+       lo->ldo_stripe = NULL;
+       lo->ldo_dir_stripes_allocated = 0;
+       lo->ldo_dir_stripe_count = 0;
+       dt->do_index_ops = &lod_index_ops;
 
-       lod_obj_inc_layout_gen(lo);
-out:
-       if (rc)
-               lod_striping_free(env, lo);
        RETURN(rc);
 }
 
-static int lod_declare_update_sync_pending(const struct lu_env *env,
-               struct lod_object *lo, struct md_layout_change *mlc,
-               struct thandle *th)
+static int lod_dir_layout_shrink(const struct lu_env *env,
+                                struct dt_object *dt,
+                                const struct md_layout_change *mlc,
+                                struct thandle *th)
 {
-       struct lod_thread_info  *info = lod_env_info(env);
-       unsigned sync_components = 0;
-       unsigned resync_components = 0;
+       struct lod_thread_info *info = lod_env_info(env);
+       struct lod_object *lo = lod_dt_obj(dt);
+       struct lod_device *lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+       struct dt_object *next = dt_object_child(dt);
+       struct lmv_user_md *lmu = mlc->mlc_buf.lb_buf;
+       __u32 final_stripe_count;
+       char *stripe_name = info->lti_key;
+       struct dt_object *dto;
+       struct lu_buf *lmv_buf = &info->lti_buf;
+       struct lmv_mds_md_v1 *lmv = &info->lti_lmv.lmv_md_v1;
+       u32 mdtidx;
+       int type = LU_SEQ_RANGE_ANY;
        int i;
        int rc;
-       ENTRY;
-
-       LASSERT(lo->ldo_flr_state == LCM_FL_SYNC_PENDING);
-       LASSERT(mlc->mlc_opc == MD_LAYOUT_RESYNC_DONE ||
-               mlc->mlc_opc == MD_LAYOUT_WRITE);
 
-       CDEBUG(D_LAYOUT, DFID ": received op %d in sync pending\n",
-              PFID(lod_object_fid(lo)), mlc->mlc_opc);
+       ENTRY;
 
-       if (mlc->mlc_opc == MD_LAYOUT_WRITE) {
-               CDEBUG(D_LAYOUT, DFID": cocurrent write to sync pending\n",
-                      PFID(lod_object_fid(lo)));
+       final_stripe_count = le32_to_cpu(lmu->lum_stripe_count);
 
-               lo->ldo_flr_state = LCM_FL_WRITE_PENDING;
-               return lod_declare_update_write_pending(env, lo, mlc, th);
-       }
+       lmv_buf->lb_buf = lmv;
+       lmv_buf->lb_len = sizeof(*lmv);
+       lmv->lmv_magic = cpu_to_le32(LMV_MAGIC_STRIPE);
+       lmv->lmv_stripe_count = cpu_to_le32(final_stripe_count);
+       lmv->lmv_hash_type = cpu_to_le32(lo->ldo_dir_hash_type) &
+                            cpu_to_le32(LMV_HASH_TYPE_MASK |
+                                        LMV_HASH_FLAG_FIXED);
+       lmv->lmv_layout_version =
+                       cpu_to_le32(lo->ldo_dir_layout_version + 1);
+       lmv->lmv_migrate_offset = 0;
+       lmv->lmv_migrate_hash = 0;
 
-       /* MD_LAYOUT_RESYNC_DONE */
+       for (i = 0; i < lo->ldo_dir_stripe_count; i++) {
+               dto = lo->ldo_stripe[i];
+               if (!dto)
+                       continue;
 
-       for (i = 0; i < lo->ldo_comp_cnt; i++) {
-               struct lod_layout_component *lod_comp;
-               int j;
+               if (i < final_stripe_count) {
+                       rc = lod_fld_lookup(env, lod,
+                                           lu_object_fid(&dto->do_lu),
+                                           &mdtidx, &type);
+                       if (rc)
+                               RETURN(rc);
 
-               lod_comp = &lo->ldo_comp_entries[i];
+                       lmv->lmv_master_mdt_index = cpu_to_le32(mdtidx);
+                       rc = lod_sub_xattr_set(env, dto, lmv_buf,
+                                              XATTR_NAME_LMV,
+                                              LU_XATTR_REPLACE, th);
+                       if (rc)
+                               RETURN(rc);
 
-               if (!(lod_comp->llc_flags & LCME_FL_STALE)) {
-                       sync_components++;
                        continue;
                }
 
-               for (j = 0; j < mlc->mlc_resync_count; j++) {
-                       if (lod_comp->llc_id != mlc->mlc_resync_ids[j])
-                               continue;
-
-                       mlc->mlc_resync_ids[j] = LCME_ID_INVAL;
-                       lod_comp->llc_flags &= ~LCME_FL_STALE;
-                       resync_components++;
-                       break;
-               }
-       }
+               dt_write_lock(env, dto, DT_TGT_CHILD);
+               rc = lod_sub_ref_del(env, dto, th);
+               dt_write_unlock(env, dto);
+               if (rc)
+                       RETURN(rc);
 
-       /* valid check */
-       for (i = 0; i < mlc->mlc_resync_count; i++) {
-               if (mlc->mlc_resync_ids[i] == LCME_ID_INVAL)
-                       continue;
+               rc = lod_sub_destroy(env, dto, th);
+               if (rc)
+                       RETURN(rc);
 
-               CDEBUG(D_LAYOUT, DFID": lcme id %u (%d / %zd) not exist "
-                      "or already synced\n", PFID(lod_object_fid(lo)),
-                      mlc->mlc_resync_ids[i], i, mlc->mlc_resync_count);
-               GOTO(out, rc = -EINVAL);
-       }
+               snprintf(stripe_name, sizeof(info->lti_key), DFID":%d",
+                        PFID(lu_object_fid(&dto->do_lu)), i);
 
-       if (!sync_components || (mlc->mlc_resync_count && !resync_components)) {
-               CDEBUG(D_LAYOUT, DFID": no mirror in sync\n",
-                      PFID(lod_object_fid(lo)));
+               rc = lod_sub_delete(env, next,
+                                   (const struct dt_key *)stripe_name, th);
+               if (rc)
+                       RETURN(rc);
 
-               /* tend to return an error code here to prevent
-                * the MDT from setting SoM attribute */
-               GOTO(out, rc = -EINVAL);
+               rc = lod_sub_ref_del(env, next, th);
+               if (rc)
+                       RETURN(rc);
        }
 
-       CDEBUG(D_LAYOUT, DFID": resynced %u/%zu components\n",
-              PFID(lod_object_fid(lo)),
-              resync_components, mlc->mlc_resync_count);
+       rc = lod_fld_lookup(env, lod, lu_object_fid(&dt->do_lu), &mdtidx,
+                           &type);
+       if (rc)
+               RETURN(rc);
 
-       lo->ldo_flr_state = LCM_FL_RDONLY;
-       lod_obj_inc_layout_gen(lo);
+       lmv->lmv_magic = cpu_to_le32(LMV_MAGIC_V1);
+       lmv->lmv_master_mdt_index = cpu_to_le32(mdtidx);
+       rc = lod_sub_xattr_set(env, next, lmv_buf, XATTR_NAME_LMV,
+                              LU_XATTR_REPLACE, th);
+       if (rc)
+               RETURN(rc);
 
-       info->lti_buf.lb_len = lod_comp_md_size(lo, false);
-       rc = lod_sub_declare_xattr_set(env, lod_object_child(lo),
-                                      &info->lti_buf, XATTR_NAME_LOV, 0, th);
-       EXIT;
+       for (i = final_stripe_count; i < lo->ldo_dir_stripe_count; i++) {
+               dto = lo->ldo_stripe[i];
+               if (dto)
+                       dt_object_put(env, dto);
+       }
+       lo->ldo_dir_stripe_count = final_stripe_count;
 
-out:
-       if (rc)
-               lod_striping_free(env, lo);
        RETURN(rc);
 }
 
+static mlc_handler dir_mlc_declare_ops[MD_LAYOUT_MAX] = {
+       [MD_LAYOUT_ATTACH] = lod_dir_declare_layout_attach,
+       [MD_LAYOUT_DETACH] = lod_dir_declare_layout_detach,
+       [MD_LAYOUT_SHRINK] = lod_dir_declare_layout_shrink,
+       [MD_LAYOUT_SPLIT]  = lod_dir_declare_layout_split,
+};
+
+static mlc_handler dir_mlc_ops[MD_LAYOUT_MAX] = {
+       [MD_LAYOUT_DETACH] = lod_dir_layout_detach,
+       [MD_LAYOUT_SHRINK] = lod_dir_layout_shrink,
+};
+
 static int lod_declare_layout_change(const struct lu_env *env,
                struct dt_object *dt, struct md_layout_change *mlc,
                struct thandle *th)
@@ -6480,8 +8890,15 @@ static int lod_declare_layout_change(const struct lu_env *env,
        struct lod_thread_info  *info = lod_env_info(env);
        struct lod_object *lo = lod_dt_obj(dt);
        int rc;
+
        ENTRY;
 
+       if (S_ISDIR(dt->do_lu.lo_header->loh_attr)) {
+               LASSERT(dir_mlc_declare_ops[mlc->mlc_opc]);
+               rc = dir_mlc_declare_ops[mlc->mlc_opc](env, dt, mlc, th);
+               RETURN(rc);
+       }
+
        if (!S_ISREG(dt->do_lu.lo_header->loh_attr) || !dt_object_exists(dt) ||
            dt_object_remote(dt_object_child(dt)))
                RETURN(-EINVAL);
@@ -6529,16 +8946,24 @@ static int lod_layout_change(const struct lu_env *env, struct dt_object *dt,
        struct lod_object *lo = lod_dt_obj(dt);
        int rc;
 
+       ENTRY;
+
+       if (S_ISDIR(dt->do_lu.lo_header->loh_attr)) {
+               LASSERT(dir_mlc_ops[mlc->mlc_opc]);
+               rc = dir_mlc_ops[mlc->mlc_opc](env, dt, mlc, th);
+               RETURN(rc);
+       }
+
        rc = lod_striped_create(env, dt, attr, NULL, th);
        if (!rc && layout_attr->la_valid & LA_LAYOUT_VERSION) {
                layout_attr->la_layout_version |= lo->ldo_layout_gen;
                rc = lod_attr_set(env, dt, layout_attr, th);
        }
 
-       return rc;
+       RETURN(rc);
 }
 
-struct dt_object_operations lod_obj_ops = {
+const struct dt_object_operations lod_obj_ops = {
        .do_read_lock           = lod_read_lock,
        .do_write_lock          = lod_write_lock,
        .do_read_unlock         = lod_read_unlock,
@@ -6607,11 +9032,11 @@ static ssize_t lod_declare_write(const struct lu_env *env,
  */
 static ssize_t lod_write(const struct lu_env *env, struct dt_object *dt,
                         const struct lu_buf *buf, loff_t *pos,
-                        struct thandle *th, int iq)
+                        struct thandle *th)
 {
        LASSERT(S_ISREG(dt->do_lu.lo_header->loh_attr) ||
                S_ISLNK(dt->do_lu.lo_header->loh_attr));
-       return lod_sub_write(env, dt_object_child(dt), buf, pos, th, iq);
+       return lod_sub_write(env, dt_object_child(dt), buf, pos, th);
 }
 
 static int lod_declare_punch(const struct lu_env *env, struct dt_object *dt,
@@ -6639,7 +9064,7 @@ static int lod_punch(const struct lu_env *env, struct dt_object *dt,
  * body_ops themselves will check file type inside, see lod_read/write/punch for
  * details.
  */
-const struct dt_body_operations lod_body_ops = {
+static const struct dt_body_operations lod_body_ops = {
        .dbo_read               = lod_read,
        .dbo_declare_write      = lod_declare_write,
        .dbo_write              = lod_write,
@@ -6672,16 +9097,8 @@ static int lod_object_init(const struct lu_env *env, struct lu_object *lo,
        ENTRY;
 
        rc = lod_fld_lookup(env, lod, lu_object_fid(lo), &idx, &type);
-       if (rc != 0) {
-               /* Note: Sometimes, it will Return EAGAIN here, see
-                * ptrlpc_import_delay_req(), which might confuse
-                * lu_object_find_at() and make it wait there incorrectly.
-                * so we convert it to EIO here.*/
-               if (rc == -EAGAIN)
-                       rc = -EIO;
-
+       if (rc != 0)
                RETURN(rc);
-       }
 
        if (type == LU_SEQ_RANGE_MDT &&
            idx == lu_site2seq(lo->lo_dev->ld_site)->ss_node_id) {
@@ -6698,7 +9115,7 @@ static int lod_object_init(const struct lu_env *env, struct lu_object *lo,
 
        if (ltd != NULL) {
                if (ltd->ltd_tgts_size > idx &&
-                   cfs_bitmap_check(ltd->ltd_tgt_bitmap, idx)) {
+                   test_bit(idx, ltd->ltd_tgt_bitmap)) {
                        tgt = LTD_TGT(ltd, idx);
 
                        LASSERT(tgt != NULL);
@@ -6736,9 +9153,18 @@ static int lod_object_init(const struct lu_env *env, struct lu_object *lo,
 void lod_striping_free_nolock(const struct lu_env *env, struct lod_object *lo)
 {
        struct lod_layout_component *lod_comp;
+       __u32 obj_attr = lo->ldo_obj.do_lu.lo_header->loh_attr;
        int i, j;
 
-       if (lo->ldo_stripe != NULL) {
+       if (unlikely(lo->ldo_is_foreign)) {
+               if (S_ISREG(obj_attr)) {
+                       lod_free_foreign_lov(lo);
+                       lo->ldo_comp_cached = 0;
+               } else if (S_ISDIR(obj_attr)) {
+                       lod_free_foreign_lmv(lo);
+                       lo->ldo_dir_stripe_loaded = 0;
+               }
+       } else if (lo->ldo_stripe != NULL) {
                LASSERT(lo->ldo_comp_entries == NULL);
                LASSERT(lo->ldo_dir_stripes_allocated > 0);
 
@@ -6753,6 +9179,7 @@ void lod_striping_free_nolock(const struct lu_env *env, struct lod_object *lo)
                lo->ldo_dir_stripes_allocated = 0;
                lo->ldo_dir_stripe_loaded = 0;
                lo->ldo_dir_stripe_count = 0;
+               lo->ldo_obj.do_index_ops = NULL;
        } else if (lo->ldo_comp_entries != NULL) {
                for (i = 0; i < lo->ldo_comp_cnt; i++) {
                        /* free lod_layout_component::llc_stripe array */
@@ -6766,13 +9193,11 @@ void lod_striping_free_nolock(const struct lu_env *env, struct lod_object *lo)
                                        lu_object_put(env,
                                               &lod_comp->llc_stripe[j]->do_lu);
                        }
-                       OBD_FREE(lod_comp->llc_stripe,
-                                sizeof(struct dt_object *) *
-                                lod_comp->llc_stripes_allocated);
+                       OBD_FREE_PTR_ARRAY(lod_comp->llc_stripe,
+                                          lod_comp->llc_stripes_allocated);
                        lod_comp->llc_stripe = NULL;
-                       OBD_FREE(lod_comp->llc_ost_indices,
-                                sizeof(__u32) *
-                                lod_comp->llc_stripes_allocated);
+                       OBD_FREE_PTR_ARRAY(lod_comp->llc_ost_indices,
+                                          lod_comp->llc_stripes_allocated);
                        lod_comp->llc_ost_indices = NULL;
                        lod_comp->llc_stripes_allocated = 0;
                }
@@ -6801,6 +9226,7 @@ static void lod_object_free(const struct lu_env *env, struct lu_object *o)
        /* release all underlying object pinned */
        lod_striping_free(env, lo);
        lu_object_fini(o);
+       /* lo doesn't contain a lu_object_header, so we don't need call_rcu */
        OBD_SLAB_FREE_PTR(lo, lod_object_kmem);
 }
 
@@ -6830,7 +9256,7 @@ static int lod_object_print(const struct lu_env *env, void *cookie,
        return (*p)(env, cookie, LUSTRE_LOD_NAME"-object@%p", o);
 }
 
-struct lu_object_operations lod_lu_obj_ops = {
+const struct lu_object_operations lod_lu_obj_ops = {
        .loo_object_init        = lod_object_init,
        .loo_object_free        = lod_object_free,
        .loo_object_release     = lod_object_release,