Whamcloud - gitweb
LU-12624 lod: alloc dir stripes by QoS
[fs/lustre-release.git] / lustre / lmv / lmv_obd.c
index 74a29be..8af14da 100644 (file)
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,7 +23,7 @@
  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2015, Intel Corporation.
+ * Copyright (c) 2011, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -35,7 +31,8 @@
  */
 
 #define DEBUG_SUBSYSTEM S_LMV
-#include <linux/slab.h>
+
+#include <linux/file.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/user_namespace.h>
@@ -49,7 +46,6 @@
 #include <linux/seq_file.h>
 #include <linux/namei.h>
 
-#include <lustre/lustre_idl.h>
 #include <obd_support.h>
 #include <lustre_lib.h>
 #include <lustre_net.h>
 #include <lprocfs_status.h>
 #include <cl_object.h>
 #include <lustre_fid.h>
-#include <lustre_ioctl.h>
+#include <uapi/linux/lustre/lustre_ioctl.h>
 #include <lustre_kernelcomm.h>
 #include "lmv_internal.h"
 
 static int lmv_check_connect(struct obd_device *obd);
 
-static void lmv_activate_target(struct lmv_obd *lmv,
-                                struct lmv_tgt_desc *tgt,
-                                int activate)
+void lmv_activate_target(struct lmv_obd *lmv, struct lmv_tgt_desc *tgt,
+                        int activate)
 {
-        if (tgt->ltd_active == activate)
-                return;
+       if (tgt->ltd_active == activate)
+               return;
 
-        tgt->ltd_active = activate;
-        lmv->desc.ld_active_tgt_count += (activate ? 1 : -1);
+       tgt->ltd_active = activate;
+       lmv->lmv_mdt_descs.ltd_lmv_desc.ld_active_tgt_count +=
+               (activate ? 1 : -1);
 
        tgt->ltd_exp->exp_obd->obd_inactive = !activate;
 }
@@ -88,50 +84,47 @@ static int lmv_set_mdc_active(struct lmv_obd *lmv,
                              const struct obd_uuid *uuid,
                              int activate)
 {
-       struct lmv_tgt_desc     *tgt = NULL;
-       struct obd_device       *obd;
-       __u32                    i;
-       int                      rc = 0;
+       struct lu_tgt_desc *tgt = NULL;
+       struct obd_device *obd;
+       int rc = 0;
+
        ENTRY;
 
        CDEBUG(D_INFO, "Searching in lmv %p for uuid %s (activate=%d)\n",
                        lmv, uuid->uuid, activate);
 
        spin_lock(&lmv->lmv_lock);
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               tgt = lmv->tgts[i];
-               if (tgt == NULL || tgt->ltd_exp == NULL)
-                       continue;
-
-               CDEBUG(D_INFO, "Target idx %d is %s conn %#llx\n", i,
-                      tgt->ltd_uuid.uuid, tgt->ltd_exp->exp_handle.h_cookie);
+       lmv_foreach_connected_tgt(lmv, tgt) {
+               CDEBUG(D_INFO, "Target idx %d is %s conn %#llx\n",
+                      tgt->ltd_index, tgt->ltd_uuid.uuid,
+                      tgt->ltd_exp->exp_handle.h_cookie);
 
                if (obd_uuid_equals(uuid, &tgt->ltd_uuid))
                        break;
        }
 
-        if (i == lmv->desc.ld_tgt_count)
-                GOTO(out_lmv_lock, rc = -EINVAL);
+       if (!tgt)
+               GOTO(out_lmv_lock, rc = -EINVAL);
 
-        obd = class_exp2obd(tgt->ltd_exp);
-        if (obd == NULL)
-                GOTO(out_lmv_lock, rc = -ENOTCONN);
+       obd = class_exp2obd(tgt->ltd_exp);
+       if (obd == NULL)
+               GOTO(out_lmv_lock, rc = -ENOTCONN);
 
-        CDEBUG(D_INFO, "Found OBD %s=%s device %d (%p) type %s at LMV idx %d\n",
-               obd->obd_name, obd->obd_uuid.uuid, obd->obd_minor, obd,
-               obd->obd_type->typ_name, i);
-        LASSERT(strcmp(obd->obd_type->typ_name, LUSTRE_MDC_NAME) == 0);
+       CDEBUG(D_INFO, "Found OBD %s=%s device %d (%p) type %s at LMV idx %d\n",
+              obd->obd_name, obd->obd_uuid.uuid, obd->obd_minor, obd,
+              obd->obd_type->typ_name, tgt->ltd_index);
+       LASSERT(strcmp(obd->obd_type->typ_name, LUSTRE_MDC_NAME) == 0);
 
-        if (tgt->ltd_active == activate) {
-                CDEBUG(D_INFO, "OBD %p already %sactive!\n", obd,
-                       activate ? "" : "in");
-                GOTO(out_lmv_lock, rc);
-        }
+       if (tgt->ltd_active == activate) {
+               CDEBUG(D_INFO, "OBD %p already %sactive!\n", obd,
+                      activate ? "" : "in");
+               GOTO(out_lmv_lock, rc);
+       }
 
-        CDEBUG(D_INFO, "Marking OBD %p %sactive\n", obd,
-               activate ? "" : "in");
-        lmv_activate_target(lmv, tgt, activate);
-        EXIT;
+       CDEBUG(D_INFO, "Marking OBD %p %sactive\n", obd,
+              activate ? "" : "in");
+       lmv_activate_target(lmv, tgt, activate);
+       EXIT;
 
  out_lmv_lock:
        spin_unlock(&lmv->lmv_lock);
@@ -140,14 +133,14 @@ static int lmv_set_mdc_active(struct lmv_obd *lmv,
 
 struct obd_uuid *lmv_get_uuid(struct obd_export *exp)
 {
-       struct lmv_obd          *lmv = &exp->exp_obd->u.lmv;
-       struct lmv_tgt_desc     *tgt = lmv->tgts[0];
+       struct lmv_obd *lmv = &exp->exp_obd->u.lmv;
+       struct lmv_tgt_desc *tgt = lmv_tgt(lmv, 0);
 
        return (tgt == NULL) ? NULL : obd_get_uuid(tgt->ltd_exp);
 }
 
 static int lmv_notify(struct obd_device *obd, struct obd_device *watched,
-                      enum obd_notify_event ev, void *data)
+                     enum obd_notify_event ev)
 {
         struct obd_connect_data *conn_data;
         struct lmv_obd          *lmv = &obd->u.lmv;
@@ -186,13 +179,13 @@ static int lmv_notify(struct obd_device *obd, struct obd_device *watched,
                obd->obd_self_export->exp_connect_data = *conn_data;
        }
 
-        /*
-         * Pass the notification up the chain.
-         */
-        if (obd->obd_observer)
-                rc = obd_notify(obd->obd_observer, watched, ev, data);
+       /*
+        * Pass the notification up the chain.
+        */
+       if (obd->obd_observer)
+               rc = obd_notify(obd->obd_observer, watched, ev);
 
-        RETURN(rc);
+       RETURN(rc);
 }
 
 static int lmv_connect(const struct lu_env *env,
@@ -215,33 +208,27 @@ static int lmv_connect(const struct lu_env *env,
        exp = class_conn2export(&conn);
 
        lmv->connected = 0;
-       lmv->cluuid = *cluuid;
        lmv->conn_data = *data;
+       lmv->lmv_cache = localdata;
 
-       if (lmv->targets_proc_entry == NULL) {
-               lmv->targets_proc_entry = lprocfs_register("target_obds",
-                                                          obd->obd_proc_entry,
-                                                          NULL, NULL);
-               if (IS_ERR(lmv->targets_proc_entry)) {
-                       CERROR("%s: cannot register "
-                              "/proc/fs/lustre/%s/%s/target_obds\n",
-                              obd->obd_name, obd->obd_type->typ_name,
-                              obd->obd_name);
-                       lmv->targets_proc_entry = NULL;
-               }
+       lmv->lmv_tgts_kobj = kobject_create_and_add("target_obds",
+                                                   &obd->obd_kset.kobj);
+       if (!lmv->lmv_tgts_kobj) {
+               CERROR("%s: cannot create /sys/fs/lustre/%s/%s/target_obds\n",
+                      obd->obd_name, obd->obd_type->typ_name, obd->obd_name);
        }
 
        rc = lmv_check_connect(obd);
        if (rc != 0)
-               GOTO(out_proc, rc);
+               GOTO(out_sysfs, rc);
 
        *pexp = exp;
 
        RETURN(rc);
 
-out_proc:
-       if (lmv->targets_proc_entry != NULL)
-               lprocfs_remove(&lmv->targets_proc_entry);
+out_sysfs:
+       if (lmv->lmv_tgts_kobj)
+               kobject_put(lmv->lmv_tgts_kobj);
 
        class_disconnect(exp);
 
@@ -251,21 +238,22 @@ out_proc:
 static int lmv_init_ea_size(struct obd_export *exp, __u32 easize,
                            __u32 def_easize)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       __u32                    i;
-       int                      rc = 0;
-       int                      change = 0;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int change = 0;
+       int rc = 0;
+
        ENTRY;
 
-        if (lmv->max_easize < easize) {
-                lmv->max_easize = easize;
-                change = 1;
-        }
-        if (lmv->max_def_easize < def_easize) {
-                lmv->max_def_easize = def_easize;
-                change = 1;
-        }
+       if (lmv->max_easize < easize) {
+               lmv->max_easize = easize;
+               change = 1;
+       }
+       if (lmv->max_def_easize < def_easize) {
+               lmv->max_def_easize = def_easize;
+               change = 1;
+       }
 
        if (change == 0)
                RETURN(0);
@@ -273,18 +261,14 @@ static int lmv_init_ea_size(struct obd_export *exp, __u32 easize,
        if (lmv->connected == 0)
                RETURN(0);
 
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               struct lmv_tgt_desc *tgt = lmv->tgts[i];
-
-               if (tgt == NULL || tgt->ltd_exp == NULL || !tgt->ltd_active) {
-                       CWARN("%s: NULL export for %d\n", obd->obd_name, i);
+       lmv_foreach_connected_tgt(lmv, tgt) {
+               if (!tgt->ltd_active)
                        continue;
-               }
 
                rc = md_init_ea_size(tgt->ltd_exp, easize, def_easize);
                if (rc) {
                        CERROR("%s: obd_init_ea_size() failed on MDT target %d:"
-                              " rc = %d\n", obd->obd_name, i, rc);
+                              " rc = %d\n", obd->obd_name, tgt->ltd_index, rc);
                        break;
                }
        }
@@ -296,33 +280,30 @@ static int lmv_init_ea_size(struct obd_export *exp, __u32 easize,
 int lmv_connect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
 {
         struct lmv_obd          *lmv = &obd->u.lmv;
-        struct obd_uuid         *cluuid = &lmv->cluuid;
-        struct obd_uuid          lmv_mdc_uuid = { "LMV_MDC_UUID" };
         struct obd_device       *mdc_obd;
         struct obd_export       *mdc_exp;
         struct lu_fld_target     target;
         int                      rc;
         ENTRY;
 
-        mdc_obd = class_find_client_obd(&tgt->ltd_uuid, LUSTRE_MDC_NAME,
-                                        &obd->obd_uuid);
-        if (!mdc_obd) {
-                CERROR("target %s not attached\n", tgt->ltd_uuid.uuid);
-                RETURN(-EINVAL);
-        }
+       mdc_obd = class_find_client_obd(&tgt->ltd_uuid, LUSTRE_MDC_NAME,
+                                       &obd->obd_uuid);
+       if (!mdc_obd) {
+               CERROR("target %s not attached\n", tgt->ltd_uuid.uuid);
+               RETURN(-EINVAL);
+       }
 
-        CDEBUG(D_CONFIG, "connect to %s(%s) - %s, %s FOR %s\n",
-                mdc_obd->obd_name, mdc_obd->obd_uuid.uuid,
-                tgt->ltd_uuid.uuid, obd->obd_uuid.uuid,
-                cluuid->uuid);
+       CDEBUG(D_CONFIG, "connect to %s(%s) - %s, %s\n",
+              mdc_obd->obd_name, mdc_obd->obd_uuid.uuid,
+              tgt->ltd_uuid.uuid, obd->obd_uuid.uuid);
 
-        if (!mdc_obd->obd_set_up) {
-                CERROR("target %s is not set up\n", tgt->ltd_uuid.uuid);
-                RETURN(-EINVAL);
-        }
+       if (!mdc_obd->obd_set_up) {
+               CERROR("target %s is not set up\n", tgt->ltd_uuid.uuid);
+               RETURN(-EINVAL);
+       }
 
-        rc = obd_connect(NULL, &mdc_exp, mdc_obd, &lmv_mdc_uuid,
-                         &lmv->conn_data, NULL);
+       rc = obd_connect(NULL, &mdc_exp, mdc_obd, &obd->obd_uuid,
+                        &lmv->conn_data, lmv->lmv_cache);
         if (rc) {
                 CERROR("target %s connect error %d\n", tgt->ltd_uuid.uuid, rc);
                 RETURN(rc);
@@ -335,82 +316,75 @@ int lmv_connect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
        if (rc)
                RETURN(rc);
 
-        target.ft_srv = NULL;
-        target.ft_exp = mdc_exp;
-        target.ft_idx = tgt->ltd_idx;
+       target.ft_srv = NULL;
+       target.ft_exp = mdc_exp;
+       target.ft_idx = tgt->ltd_index;
 
-        fld_client_add_target(&lmv->lmv_fld, &target);
+       fld_client_add_target(&lmv->lmv_fld, &target);
 
-        rc = obd_register_observer(mdc_obd, obd);
-        if (rc) {
-                obd_disconnect(mdc_exp);
-                CERROR("target %s register_observer error %d\n",
-                       tgt->ltd_uuid.uuid, rc);
-                RETURN(rc);
-        }
+       rc = obd_register_observer(mdc_obd, obd);
+       if (rc) {
+               obd_disconnect(mdc_exp);
+               CERROR("target %s register_observer error %d\n",
+                      tgt->ltd_uuid.uuid, rc);
+               RETURN(rc);
+       }
 
-        if (obd->obd_observer) {
-                /*
-                 * Tell the observer about the new target.
-                 */
+       if (obd->obd_observer) {
+               /*
+                * Tell the observer about the new target.
+                */
                rc = obd_notify(obd->obd_observer, mdc_exp->exp_obd,
-                               OBD_NOTIFY_ACTIVE,
-                               (void *)(tgt - lmv->tgts[0]));
+                               OBD_NOTIFY_ACTIVE);
                if (rc) {
                        obd_disconnect(mdc_exp);
                        RETURN(rc);
                }
-        }
+       }
 
        tgt->ltd_active = 1;
        tgt->ltd_exp = mdc_exp;
-       lmv->desc.ld_active_tgt_count++;
+       lmv->lmv_mdt_descs.ltd_lmv_desc.ld_active_tgt_count++;
 
        md_init_ea_size(tgt->ltd_exp, lmv->max_easize, lmv->max_def_easize);
 
+       rc = lu_qos_add_tgt(&lmv->lmv_qos, tgt);
+       if (rc) {
+               obd_disconnect(mdc_exp);
+               RETURN(rc);
+       }
+
        CDEBUG(D_CONFIG, "Connected to %s(%s) successfully (%d)\n",
                mdc_obd->obd_name, mdc_obd->obd_uuid.uuid,
                atomic_read(&obd->obd_refcount));
 
-       if (lmv->targets_proc_entry != NULL) {
-               struct proc_dir_entry *mdc_symlink;
-
-               LASSERT(mdc_obd->obd_type != NULL);
-               LASSERT(mdc_obd->obd_type->typ_name != NULL);
-               mdc_symlink = lprocfs_add_symlink(mdc_obd->obd_name,
-                                                 lmv->targets_proc_entry,
-                                                 "../../../%s/%s",
-                                                 mdc_obd->obd_type->typ_name,
-                                                 mdc_obd->obd_name);
-               if (mdc_symlink == NULL) {
-                       CERROR("cannot register LMV target "
-                              "/proc/fs/lustre/%s/%s/target_obds/%s\n",
-                              obd->obd_type->typ_name, obd->obd_name,
-                              mdc_obd->obd_name);
-               }
-       }
+       lmv_statfs_check_update(obd, tgt);
+
+       if (lmv->lmv_tgts_kobj)
+               /* Even if we failed to create the link, that's fine */
+               rc = sysfs_create_link(lmv->lmv_tgts_kobj,
+                                      &mdc_obd->obd_kset.kobj,
+                                      mdc_obd->obd_name);
        RETURN(0);
 }
 
-static void lmv_del_target(struct lmv_obd *lmv, int index)
+static void lmv_del_target(struct lmv_obd *lmv, struct lu_tgt_desc *tgt)
 {
-       if (lmv->tgts[index] == NULL)
-               return;
-
-       OBD_FREE_PTR(lmv->tgts[index]);
-       lmv->tgts[index] = NULL;
-       return;
+       LASSERT(tgt);
+       ltd_del_tgt(&lmv->lmv_mdt_descs, tgt);
+       OBD_FREE_PTR(tgt);
 }
 
 static int lmv_add_target(struct obd_device *obd, struct obd_uuid *uuidp,
                           __u32 index, int gen)
 {
        struct obd_device *mdc_obd;
-        struct lmv_obd      *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc *tgt;
-       int                  orig_tgt_count = 0;
-        int                  rc = 0;
-        ENTRY;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       struct lu_tgt_descs *ltd = &lmv->lmv_mdt_descs;
+       int rc = 0;
+
+       ENTRY;
 
        CDEBUG(D_CONFIG, "Target uuid: %s. index %d\n", uuidp->uuid, index);
        mdc_obd = class_find_client_obd(uuidp, LUSTRE_MDC_NAME,
@@ -421,159 +395,98 @@ static int lmv_add_target(struct obd_device *obd, struct obd_uuid *uuidp,
                RETURN(-EINVAL);
        }
 
-       mutex_lock(&lmv->lmv_init_mutex);
-       if ((index < lmv->tgts_size) && (lmv->tgts[index] != NULL)) {
-               tgt = lmv->tgts[index];
-               CERROR("%s: UUID %s already assigned at LOV target index %d:"
-                      " rc = %d\n", obd->obd_name,
-                      obd_uuid2str(&tgt->ltd_uuid), index, -EEXIST);
-               mutex_unlock(&lmv->lmv_init_mutex);
-               RETURN(-EEXIST);
-       }
-
-       if (index >= lmv->tgts_size) {
-               /* We need to reallocate the lmv target array. */
-               struct lmv_tgt_desc **newtgts, **old = NULL;
-               __u32 newsize = 1;
-               __u32 oldsize = 0;
-
-               while (newsize < index + 1)
-                       newsize = newsize << 1;
-               OBD_ALLOC(newtgts, sizeof(*newtgts) * newsize);
-               if (newtgts == NULL) {
-                       mutex_unlock(&lmv->lmv_init_mutex);
-                       RETURN(-ENOMEM);
-               }
-
-               if (lmv->tgts_size) {
-                       memcpy(newtgts, lmv->tgts,
-                              sizeof(*newtgts) * lmv->tgts_size);
-                       old = lmv->tgts;
-                       oldsize = lmv->tgts_size;
-               }
-
-               lmv->tgts = newtgts;
-               lmv->tgts_size = newsize;
-               smp_rmb();
-               if (old)
-                       OBD_FREE(old, sizeof(*old) * oldsize);
-
-               CDEBUG(D_CONFIG, "tgts: %p size: %d\n", lmv->tgts,
-                      lmv->tgts_size);
-       }
-
        OBD_ALLOC_PTR(tgt);
-       if (!tgt) {
-               mutex_unlock(&lmv->lmv_init_mutex);
+       if (!tgt)
                RETURN(-ENOMEM);
-       }
 
        mutex_init(&tgt->ltd_fid_mutex);
-       tgt->ltd_idx = index;
+       tgt->ltd_index = index;
        tgt->ltd_uuid = *uuidp;
        tgt->ltd_active = 0;
-       lmv->tgts[index] = tgt;
-       if (index >= lmv->desc.ld_tgt_count) {
-               orig_tgt_count = lmv->desc.ld_tgt_count;
-               lmv->desc.ld_tgt_count = index + 1;
-       }
 
-       if (lmv->connected == 0) {
+       mutex_lock(&ltd->ltd_mutex);
+       rc = ltd_add_tgt(ltd, tgt);
+       mutex_unlock(&ltd->ltd_mutex);
+
+       if (rc)
+               GOTO(out_tgt, rc);
+
+       if (!lmv->connected)
                /* lmv_check_connect() will connect this target. */
-               mutex_unlock(&lmv->lmv_init_mutex);
                RETURN(0);
-       }
 
-       /* Otherwise let's connect it ourselves */
-       mutex_unlock(&lmv->lmv_init_mutex);
        rc = lmv_connect_mdc(obd, tgt);
-       if (rc != 0) {
-               spin_lock(&lmv->lmv_lock);
-               if (lmv->desc.ld_tgt_count == index + 1)
-                       lmv->desc.ld_tgt_count = orig_tgt_count;
-               memset(tgt, 0, sizeof(*tgt));
-               spin_unlock(&lmv->lmv_lock);
-       } else {
+       if (!rc) {
                int easize = sizeof(struct lmv_stripe_md) +
-                       lmv->desc.ld_tgt_count * sizeof(struct lu_fid);
+                       lmv->lmv_mdt_count * sizeof(struct lu_fid);
+
                lmv_init_ea_size(obd->obd_self_export, easize, 0);
        }
 
        RETURN(rc);
+
+out_tgt:
+       OBD_FREE_PTR(tgt);
+       return rc;
 }
 
 static int lmv_check_connect(struct obd_device *obd)
 {
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt;
-       __u32                    i;
-       int                      rc;
-       int                      easize;
-       ENTRY;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int easize;
+       int rc;
 
-        if (lmv->connected)
-                RETURN(0);
+       ENTRY;
 
-       mutex_lock(&lmv->lmv_init_mutex);
-        if (lmv->connected) {
-               mutex_unlock(&lmv->lmv_init_mutex);
-                RETURN(0);
-        }
+       if (lmv->connected)
+               RETURN(0);
 
-        if (lmv->desc.ld_tgt_count == 0) {
-               mutex_unlock(&lmv->lmv_init_mutex);
-                CERROR("%s: no targets configured.\n", obd->obd_name);
-                RETURN(-EINVAL);
-        }
+       mutex_lock(&lmv->lmv_mdt_descs.ltd_mutex);
+       if (lmv->connected)
+               GOTO(unlock, rc = 0);
 
-       LASSERT(lmv->tgts != NULL);
+       if (!lmv->lmv_mdt_count) {
+               CERROR("%s: no targets configured: rc = -EINVAL\n",
+                      obd->obd_name);
+               GOTO(unlock, rc = -EINVAL);
+       }
 
-       if (lmv->tgts[0] == NULL) {
-               mutex_unlock(&lmv->lmv_init_mutex);
-               CERROR("%s: no target configured for index 0.\n",
+       if (!lmv_mdt0_inited(lmv)) {
+               CERROR("%s: no target configured for index 0: rc = -EINVAL.\n",
                       obd->obd_name);
-               RETURN(-EINVAL);
+               GOTO(unlock, rc = -EINVAL);
        }
 
        CDEBUG(D_CONFIG, "Time to connect %s to %s\n",
-              lmv->cluuid.uuid, obd->obd_name);
+              obd->obd_uuid.uuid, obd->obd_name);
 
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               tgt = lmv->tgts[i];
-               if (tgt == NULL)
-                       continue;
+       lmv_foreach_tgt(lmv, tgt) {
                rc = lmv_connect_mdc(obd, tgt);
                if (rc)
                        GOTO(out_disc, rc);
        }
 
        lmv->connected = 1;
-       easize = lmv_mds_md_size(lmv->desc.ld_tgt_count, LMV_MAGIC);
+       easize = lmv_mds_md_size(lmv->lmv_mdt_count, LMV_MAGIC);
        lmv_init_ea_size(obd->obd_self_export, easize, 0);
-       mutex_unlock(&lmv->lmv_init_mutex);
-       RETURN(0);
+       EXIT;
+unlock:
+       mutex_unlock(&lmv->lmv_mdt_descs.ltd_mutex);
+
+       return rc;
 
- out_disc:
-        while (i-- > 0) {
-                int rc2;
-               tgt = lmv->tgts[i];
-               if (tgt == NULL)
+out_disc:
+       lmv_foreach_tgt(lmv, tgt) {
+               tgt->ltd_active = 0;
+               if (!tgt->ltd_exp)
                        continue;
-                tgt->ltd_active = 0;
-                if (tgt->ltd_exp) {
-                        --lmv->desc.ld_active_tgt_count;
-                        rc2 = obd_disconnect(tgt->ltd_exp);
-                        if (rc2) {
-                                CERROR("LMV target %s disconnect on "
-                                       "MDC idx %d: error %d\n",
-                                       tgt->ltd_uuid.uuid, i, rc2);
-                        }
-                }
-        }
 
-       mutex_unlock(&lmv->lmv_init_mutex);
+               --lmv->lmv_mdt_descs.ltd_lmv_desc.ld_active_tgt_count;
+               obd_disconnect(tgt->ltd_exp);
+       }
 
-       RETURN(rc);
+       goto unlock;
 }
 
 static int lmv_disconnect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
@@ -593,9 +506,9 @@ static int lmv_disconnect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
                 mdc_obd->obd_fail = obd->obd_fail;
                 mdc_obd->obd_no_recov = obd->obd_no_recov;
 
-               if (lmv->targets_proc_entry != NULL)
-                       lprocfs_remove_proc_entry(mdc_obd->obd_name,
-                                                 lmv->targets_proc_entry);
+               if (lmv->lmv_tgts_kobj)
+                       sysfs_remove_link(lmv->lmv_tgts_kobj,
+                                         mdc_obd->obd_name);
        }
 
        rc = obd_fid_fini(tgt->ltd_exp->exp_obd);
@@ -622,36 +535,22 @@ static int lmv_disconnect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
 
 static int lmv_disconnect(struct obd_export *exp)
 {
-       struct obd_device       *obd = class_exp2obd(exp);
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       int                      rc;
-       __u32                    i;
-       ENTRY;
+       struct obd_device *obd = class_exp2obd(exp);
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
 
-        if (!lmv->tgts)
-                goto out_local;
+       ENTRY;
 
-        for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
-                        continue;
+       lmv_foreach_connected_tgt(lmv, tgt)
+               lmv_disconnect_mdc(obd, tgt);
 
-               lmv_disconnect_mdc(obd, lmv->tgts[i]);
-        }
+       if (lmv->lmv_tgts_kobj)
+               kobject_put(lmv->lmv_tgts_kobj);
 
-       if (lmv->targets_proc_entry != NULL)
-               lprocfs_remove(&lmv->targets_proc_entry);
-       else
-               CERROR("/proc/fs/lustre/%s/%s/target_obds missing\n",
-                      obd->obd_type->typ_name, obd->obd_name);
-
-out_local:
-        /*
-         * This is the case when no real connection is established by
-         * lmv_check_connect().
-         */
-        if (!lmv->connected)
-                class_export_put(exp);
-        rc = class_disconnect(exp);
+       if (!lmv->connected)
+               class_export_put(exp);
+       rc = class_disconnect(exp);
        lmv->connected = 0;
 
        RETURN(rc);
@@ -660,17 +559,17 @@ out_local:
 static int lmv_fid2path(struct obd_export *exp, int len, void *karg,
                        void __user *uarg)
 {
-       struct obd_device       *obddev = class_exp2obd(exp);
-       struct lmv_obd          *lmv = &obddev->u.lmv;
+       struct obd_device *obddev = class_exp2obd(exp);
+       struct lmv_obd *lmv = &obddev->u.lmv;
        struct getinfo_fid2path *gf;
-       struct lmv_tgt_desc     *tgt;
+       struct lmv_tgt_desc *tgt;
        struct getinfo_fid2path *remote_gf = NULL;
-       struct lu_fid           root_fid;
-       int                     remote_gf_size = 0;
-       int                     rc;
+       struct lu_fid root_fid;
+       int remote_gf_size = 0;
+       int rc;
 
        gf = karg;
-       tgt = lmv_find_target(lmv, &gf->gf_fid);
+       tgt = lmv_fid2tgt(lmv, &gf->gf_fid);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
@@ -687,21 +586,21 @@ repeat_fid2path:
        if (remote_gf != NULL) {
                struct getinfo_fid2path *ori_gf;
                char *ptr;
+               int len;
 
                ori_gf = (struct getinfo_fid2path *)karg;
-               if (strlen(ori_gf->gf_u.gf_path) +
-                   strlen(gf->gf_u.gf_path) > ori_gf->gf_pathlen)
+               if (strlen(ori_gf->gf_u.gf_path) + 1 +
+                   strlen(gf->gf_u.gf_path) + 1 > ori_gf->gf_pathlen)
                        GOTO(out_fid2path, rc = -EOVERFLOW);
 
                ptr = ori_gf->gf_u.gf_path;
 
-               memmove(ptr + strlen(gf->gf_u.gf_path) + 1, ptr,
-                       strlen(ori_gf->gf_u.gf_path));
-
-               strncpy(ptr, gf->gf_u.gf_path,
-                       strlen(gf->gf_u.gf_path));
-               ptr += strlen(gf->gf_u.gf_path);
-               *ptr = '/';
+               len = strlen(gf->gf_u.gf_path);
+               /* move the current path to the right to release space
+                * for closer-to-root part */
+               memmove(ptr + len + 1, ptr, strlen(ori_gf->gf_u.gf_path));
+               memcpy(ptr, gf->gf_u.gf_path, len);
+               ptr[len] = '/';
        }
 
        CDEBUG(D_INFO, "%s: get path %s "DFID" rec: %llu ln: %u\n",
@@ -728,7 +627,7 @@ repeat_fid2path:
                GOTO(out_fid2path, rc = -EINVAL);
        }
 
-       tgt = lmv_find_target(lmv, &gf->gf_fid);
+       tgt = lmv_fid2tgt(lmv, &gf->gf_fid);
        if (IS_ERR(tgt))
                GOTO(out_fid2path, rc = -EINVAL);
 
@@ -750,13 +649,13 @@ static int lmv_hsm_req_count(struct lmv_obd *lmv,
                             const struct hsm_user_request *hur,
                             const struct lmv_tgt_desc *tgt_mds)
 {
-       __u32                    i;
-       int                      nr = 0;
-       struct lmv_tgt_desc     *curr_tgt;
+       struct lmv_tgt_desc *curr_tgt;
+       __u32 i;
+       int nr = 0;
 
        /* count how many requests must be sent to the given target */
        for (i = 0; i < hur->hur_request.hr_itemcount; i++) {
-               curr_tgt = lmv_find_target(lmv, &hur->hur_user_item[i].hui_fid);
+               curr_tgt = lmv_fid2tgt(lmv, &hur->hur_user_item[i].hui_fid);
                if (IS_ERR(curr_tgt))
                        RETURN(PTR_ERR(curr_tgt));
                if (obd_uuid_equals(&curr_tgt->ltd_uuid, &tgt_mds->ltd_uuid))
@@ -770,15 +669,14 @@ static int lmv_hsm_req_build(struct lmv_obd *lmv,
                              const struct lmv_tgt_desc *tgt_mds,
                              struct hsm_user_request *hur_out)
 {
-       __u32                    i, nr_out;
-       struct lmv_tgt_desc     *curr_tgt;
+       __u32 i, nr_out;
+       struct lmv_tgt_desc *curr_tgt;
 
        /* build the hsm_user_request for the given target */
        hur_out->hur_request = hur_in->hur_request;
        nr_out = 0;
        for (i = 0; i < hur_in->hur_request.hr_itemcount; i++) {
-               curr_tgt = lmv_find_target(lmv,
-                                          &hur_in->hur_user_item[i].hui_fid);
+               curr_tgt = lmv_fid2tgt(lmv, &hur_in->hur_user_item[i].hui_fid);
                if (IS_ERR(curr_tgt))
                        RETURN(PTR_ERR(curr_tgt));
                if (obd_uuid_equals(&curr_tgt->ltd_uuid, &tgt_mds->ltd_uuid)) {
@@ -794,52 +692,81 @@ static int lmv_hsm_req_build(struct lmv_obd *lmv,
        RETURN(0);
 }
 
-static int lmv_hsm_ct_unregister(struct lmv_obd *lmv, unsigned int cmd, int len,
-                                struct lustre_kernelcomm *lk,
+static int lmv_hsm_ct_unregister(struct obd_device *obd, unsigned int cmd,
+                                int len, struct lustre_kernelcomm *lk,
                                 void __user *uarg)
 {
-       __u32   i;
-       int     rc;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lu_tgt_desc *tgt;
+       int rc;
+
        ENTRY;
 
        /* unregister request (call from llapi_hsm_copytool_fini) */
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               struct lmv_tgt_desc *tgt = lmv->tgts[i];
-
-               if (tgt == NULL || tgt->ltd_exp == NULL)
-                       continue;
+       lmv_foreach_connected_tgt(lmv, tgt)
                /* best effort: try to clean as much as possible
                 * (continue on error) */
                obd_iocontrol(cmd, tgt->ltd_exp, len, lk, uarg);
-       }
 
        /* Whatever the result, remove copytool from kuc groups.
         * Unreached coordinators will get EPIPE on next requests
         * and will unregister automatically.
         */
-       rc = libcfs_kkuc_group_rem(lk->lk_uid, lk->lk_group);
+       rc = libcfs_kkuc_group_rem(&obd->obd_uuid, lk->lk_uid, lk->lk_group);
 
        RETURN(rc);
 }
 
-static int lmv_hsm_ct_register(struct lmv_obd *lmv, unsigned int cmd, int len,
-                              struct lustre_kernelcomm *lk, __user void *uarg)
+static int lmv_hsm_ct_register(struct obd_device *obd, unsigned int cmd,
+                              int len, struct lustre_kernelcomm *lk,
+                              void __user *uarg)
 {
-       struct file             *filp;
-       __u32                    i, j;
-       int                      err, rc;
-       bool                     any_set = false;
-       struct kkuc_ct_data      kcd = { 0 };
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct file *filp;
+       bool any_set = false;
+       struct kkuc_ct_data *kcd;
+       size_t kcd_size;
+       struct lu_tgt_desc *tgt;
+       __u32 i;
+       int err;
+       int rc = 0;
+
        ENTRY;
 
+       filp = fget(lk->lk_wfd);
+       if (!filp)
+               RETURN(-EBADF);
+
+       if (lk->lk_flags & LK_FLG_DATANR)
+               kcd_size = offsetof(struct kkuc_ct_data,
+                                   kcd_archives[lk->lk_data_count]);
+       else
+               kcd_size = sizeof(*kcd);
+
+       OBD_ALLOC(kcd, kcd_size);
+       if (kcd == NULL)
+               GOTO(err_fput, rc = -ENOMEM);
+
+       kcd->kcd_nr_archives = lk->lk_data_count;
+       if (lk->lk_flags & LK_FLG_DATANR) {
+               kcd->kcd_magic = KKUC_CT_DATA_ARRAY_MAGIC;
+               if (lk->lk_data_count > 0)
+                       memcpy(kcd->kcd_archives, lk->lk_data,
+                              sizeof(*kcd->kcd_archives) * lk->lk_data_count);
+       } else {
+               kcd->kcd_magic = KKUC_CT_DATA_BITMAP_MAGIC;
+       }
+
+       rc = libcfs_kkuc_group_add(filp, &obd->obd_uuid, lk->lk_uid,
+                                  lk->lk_group, kcd, kcd_size);
+       OBD_FREE(kcd, kcd_size);
+       if (rc)
+               GOTO(err_fput, rc);
+
        /* All or nothing: try to register to all MDS.
         * In case of failure, unregister from previous MDS,
         * except if it because of inactive target. */
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               struct lmv_tgt_desc *tgt = lmv->tgts[i];
-
-               if (tgt == NULL || tgt->ltd_exp == NULL)
-                       continue;
+       lmv_foreach_connected_tgt(lmv, tgt) {
                err = obd_iocontrol(cmd, tgt->ltd_exp, len, lk, uarg);
                if (err) {
                        if (tgt->ltd_active) {
@@ -847,18 +774,20 @@ static int lmv_hsm_ct_register(struct lmv_obd *lmv, unsigned int cmd, int len,
                                CERROR("%s: iocontrol MDC %s on MDT"
                                       " idx %d cmd %x: err = %d\n",
                                       lmv2obd_dev(lmv)->obd_name,
-                                      tgt->ltd_uuid.uuid, i, cmd, err);
+                                      tgt->ltd_uuid.uuid, tgt->ltd_index, cmd,
+                                      err);
                                rc = err;
                                lk->lk_flags |= LK_FLG_STOP;
+                               i = tgt->ltd_index;
                                /* unregister from previous MDS */
-                               for (j = 0; j < i; j++) {
-                                       tgt = lmv->tgts[j];
-                                       if (tgt == NULL || tgt->ltd_exp == NULL)
-                                               continue;
+                               lmv_foreach_connected_tgt(lmv, tgt) {
+                                       if (tgt->ltd_index >= i)
+                                               break;
+
                                        obd_iocontrol(cmd, tgt->ltd_exp, len,
                                                      lk, uarg);
                                }
-                               RETURN(rc);
+                               GOTO(err_kkuc_rem, rc);
                        }
                        /* else: transient error.
                         * kuc will register to the missing MDT
@@ -870,56 +799,47 @@ static int lmv_hsm_ct_register(struct lmv_obd *lmv, unsigned int cmd, int len,
 
        if (!any_set)
                /* no registration done: return error */
-               RETURN(-ENOTCONN);
+               GOTO(err_kkuc_rem, rc = -ENOTCONN);
 
-       /* at least one registration done, with no failure */
-       filp = fget(lk->lk_wfd);
-       if (filp == NULL)
-               RETURN(-EBADF);
-
-       kcd.kcd_magic = KKUC_CT_DATA_MAGIC;
-       kcd.kcd_uuid = lmv->cluuid;
-       kcd.kcd_archive = lk->lk_data;
+       RETURN(0);
 
-       rc = libcfs_kkuc_group_add(filp, lk->lk_uid, lk->lk_group,
-                                  &kcd, sizeof(kcd));
-       if (rc != 0)
-               fput(filp);
+err_kkuc_rem:
+       libcfs_kkuc_group_rem(&obd->obd_uuid, lk->lk_uid, lk->lk_group);
 
-       RETURN(rc);
+err_fput:
+       fput(filp);
+       return rc;
 }
 
-
-
-
 static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
                         int len, void *karg, void __user *uarg)
 {
-       struct obd_device       *obddev = class_exp2obd(exp);
-       struct lmv_obd          *lmv = &obddev->u.lmv;
-       struct lmv_tgt_desc     *tgt = NULL;
-       __u32                    i = 0;
-       int                      rc = 0;
-       int                      set = 0;
-       __u32                    count = lmv->desc.ld_tgt_count;
+       struct obd_device *obddev = class_exp2obd(exp);
+       struct lmv_obd *lmv = &obddev->u.lmv;
+       struct lu_tgt_desc *tgt = NULL;
+       int set = 0;
+       __u32 count = lmv->lmv_mdt_count;
+       int rc = 0;
+
        ENTRY;
 
-        if (count == 0)
-                RETURN(-ENOTTY);
+       if (count == 0)
+               RETURN(-ENOTTY);
+
+       switch (cmd) {
+       case IOC_OBD_STATFS: {
+               struct obd_ioctl_data *data = karg;
+               struct obd_device *mdc_obd;
+               struct obd_statfs stat_buf = {0};
+               __u32 index;
 
-        switch (cmd) {
-        case IOC_OBD_STATFS: {
-                struct obd_ioctl_data *data = karg;
-                struct obd_device *mdc_obd;
-                struct obd_statfs stat_buf = {0};
-                __u32 index;
+               memcpy(&index, data->ioc_inlbuf2, sizeof(__u32));
 
-                memcpy(&index, data->ioc_inlbuf2, sizeof(__u32));
-                if ((index >= count))
-                        RETURN(-ENODEV);
+               if (index >= lmv->lmv_mdt_descs.ltd_tgts_size)
+                       RETURN(-ENODEV);
 
-               tgt = lmv->tgts[index];
-               if (tgt == NULL || !tgt->ltd_active)
+               tgt = lmv_tgt(lmv, index);
+               if (!tgt || !tgt->ltd_active)
                        RETURN(-ENODATA);
 
                mdc_obd = class_exp2obd(tgt->ltd_exp);
@@ -933,7 +853,7 @@ static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
                        RETURN(-EFAULT);
 
                rc = obd_statfs(NULL, tgt->ltd_exp, &stat_buf,
-                               cfs_time_shift_64(-OBD_STATFS_CACHE_SECONDS),
+                               ktime_get_seconds() - OBD_STATFS_CACHE_SECONDS,
                                0);
                if (rc)
                        RETURN(rc);
@@ -942,72 +862,50 @@ static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
                                     (int) sizeof(stat_buf))))
                        RETURN(-EFAULT);
                break;
-        }
-        case OBD_IOC_QUOTACTL: {
-                struct if_quotactl *qctl = karg;
-                struct obd_quotactl *oqctl;
+       }
+       case OBD_IOC_QUOTACTL: {
+               struct if_quotactl *qctl = karg;
+               struct obd_quotactl *oqctl;
 
                if (qctl->qc_valid == QC_MDTIDX) {
-                       if (count <= qctl->qc_idx)
-                               RETURN(-EINVAL);
-
-                       tgt = lmv->tgts[qctl->qc_idx];
-                       if (tgt == NULL || tgt->ltd_exp == NULL)
-                               RETURN(-EINVAL);
+                       tgt = lmv_tgt(lmv, qctl->qc_idx);
                } else if (qctl->qc_valid == QC_UUID) {
-                       for (i = 0; i < count; i++) {
-                               tgt = lmv->tgts[i];
-                               if (tgt == NULL)
-                                       continue;
+                       lmv_foreach_tgt(lmv, tgt) {
                                if (!obd_uuid_equals(&tgt->ltd_uuid,
                                                     &qctl->obd_uuid))
                                        continue;
 
-                                if (tgt->ltd_exp == NULL)
-                                        RETURN(-EINVAL);
-
-                                break;
-                        }
-                } else {
-                        RETURN(-EINVAL);
-                }
-
-                if (i >= count)
-                        RETURN(-EAGAIN);
+                               if (!tgt->ltd_exp)
+                                       RETURN(-EINVAL);
 
-                LASSERT(tgt != NULL && tgt->ltd_exp != NULL);
-                OBD_ALLOC_PTR(oqctl);
-                if (!oqctl)
-                        RETURN(-ENOMEM);
+                               break;
+                       }
+               } else {
+                       RETURN(-EINVAL);
+               }
 
-                QCTL_COPY(oqctl, qctl);
-                rc = obd_quotactl(tgt->ltd_exp, oqctl);
-                if (rc == 0) {
-                        QCTL_COPY(qctl, oqctl);
-                        qctl->qc_valid = QC_MDTIDX;
-                        qctl->obd_uuid = tgt->ltd_uuid;
-                }
-                OBD_FREE_PTR(oqctl);
-                break;
-        }
-        case OBD_IOC_CHANGELOG_SEND:
-        case OBD_IOC_CHANGELOG_CLEAR: {
-                struct ioc_changelog *icc = karg;
+               if (!tgt || !tgt->ltd_exp)
+                       RETURN(-EINVAL);
 
-                if (icc->icc_mdtindex >= count)
-                        RETURN(-ENODEV);
+               OBD_ALLOC_PTR(oqctl);
+               if (!oqctl)
+                       RETURN(-ENOMEM);
 
-               tgt = lmv->tgts[icc->icc_mdtindex];
-               if (tgt == NULL || tgt->ltd_exp == NULL || !tgt->ltd_active)
-                       RETURN(-ENODEV);
-               rc = obd_iocontrol(cmd, tgt->ltd_exp, sizeof(*icc), icc, NULL);
+               QCTL_COPY(oqctl, qctl);
+               rc = obd_quotactl(tgt->ltd_exp, oqctl);
+               if (rc == 0) {
+                       QCTL_COPY(qctl, oqctl);
+                       qctl->qc_valid = QC_MDTIDX;
+                       qctl->obd_uuid = tgt->ltd_uuid;
+               }
+               OBD_FREE_PTR(oqctl);
                break;
        }
        case LL_IOC_GET_CONNECT_FLAGS: {
-               tgt = lmv->tgts[0];
-               if (tgt == NULL || tgt->ltd_exp == NULL)
-                       RETURN(-ENODATA);
-               rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
+               tgt = lmv_tgt(lmv, 0);
+               rc = -ENODATA;
+               if (tgt && tgt->ltd_exp)
+                       rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
                break;
        }
        case LL_IOC_FID2MDTIDX: {
@@ -1030,9 +928,9 @@ static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
        case LL_IOC_HSM_STATE_GET:
        case LL_IOC_HSM_STATE_SET:
        case LL_IOC_HSM_ACTION: {
-               struct md_op_data       *op_data = karg;
+               struct md_op_data *op_data = karg;
 
-               tgt = lmv_find_target(lmv, &op_data->op_fid1);
+               tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
                if (IS_ERR(tgt))
                        RETURN(PTR_ERR(tgt));
 
@@ -1045,7 +943,7 @@ static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
        case LL_IOC_HSM_PROGRESS: {
                const struct hsm_progress_kernel *hpk = karg;
 
-               tgt = lmv_find_target(lmv, &hpk->hpk_fid);
+               tgt = lmv_fid2tgt(lmv, &hpk->hpk_fid);
                if (IS_ERR(tgt))
                        RETURN(PTR_ERR(tgt));
                rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
@@ -1062,22 +960,17 @@ static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
                 * or if there is a single MDS, no need to split
                 * the request. */
                if (reqcount == 1 || count == 1) {
-                       tgt = lmv_find_target(lmv,
-                                             &hur->hur_user_item[0].hui_fid);
+                       tgt = lmv_fid2tgt(lmv, &hur->hur_user_item[0].hui_fid);
                        if (IS_ERR(tgt))
                                RETURN(PTR_ERR(tgt));
                        rc = obd_iocontrol(cmd, tgt->ltd_exp, len, karg, uarg);
                } else {
                        /* split fid list to their respective MDS */
-                       for (i = 0; i < count; i++) {
+                       lmv_foreach_connected_tgt(lmv, tgt) {
                                int nr, rc1;
                                size_t reqlen;
                                struct hsm_user_request *req;
 
-                               tgt = lmv->tgts[i];
-                               if (tgt == NULL || tgt->ltd_exp == NULL)
-                                       continue;
-
                                nr = lmv_hsm_req_count(lmv, hur, tgt);
                                if (nr < 0)
                                        RETURN(nr);
@@ -1105,14 +998,14 @@ hsm_req_err:
                break;
        }
        case LL_IOC_LOV_SWAP_LAYOUTS: {
-               struct md_op_data       *op_data = karg;
-               struct lmv_tgt_desc     *tgt1, *tgt2;
+               struct md_op_data *op_data = karg;
+               struct lmv_tgt_desc *tgt1, *tgt2;
 
-               tgt1 = lmv_find_target(lmv, &op_data->op_fid1);
+               tgt1 = lmv_fid2tgt(lmv, &op_data->op_fid1);
                if (IS_ERR(tgt1))
                        RETURN(PTR_ERR(tgt1));
 
-               tgt2 = lmv_find_target(lmv, &op_data->op_fid2);
+               tgt2 = lmv_fid2tgt(lmv, &op_data->op_fid2);
                if (IS_ERR(tgt2))
                        RETURN(PTR_ERR(tgt2));
 
@@ -1120,7 +1013,7 @@ hsm_req_err:
                        RETURN(-EINVAL);
 
                /* only files on same MDT can have their layouts swapped */
-               if (tgt1->ltd_idx != tgt2->ltd_idx)
+               if (tgt1->ltd_index != tgt2->ltd_index)
                        RETURN(-EPERM);
 
                rc = obd_iocontrol(cmd, tgt1->ltd_exp, len, karg, uarg);
@@ -1129,19 +1022,16 @@ hsm_req_err:
        case LL_IOC_HSM_CT_START: {
                struct lustre_kernelcomm *lk = karg;
                if (lk->lk_flags & LK_FLG_STOP)
-                       rc = lmv_hsm_ct_unregister(lmv, cmd, len, lk, uarg);
+                       rc = lmv_hsm_ct_unregister(obddev, cmd, len, lk, uarg);
                else
-                       rc = lmv_hsm_ct_register(lmv, cmd, len, lk, uarg);
+                       rc = lmv_hsm_ct_register(obddev, cmd, len, lk, uarg);
                break;
        }
        default:
-               for (i = 0; i < count; i++) {
+               lmv_foreach_connected_tgt(lmv, tgt) {
                        struct obd_device *mdc_obd;
                        int err;
 
-                       tgt = lmv->tgts[i];
-                       if (tgt == NULL || tgt->ltd_exp == NULL)
-                               continue;
                        /* ll_umount_begin() sets force flag but for lmv, not
                         * mdc. Let's pass it through */
                        mdc_obd = class_exp2obd(tgt->ltd_exp);
@@ -1151,200 +1041,130 @@ hsm_req_err:
                                if (tgt->ltd_active) {
                                        CERROR("error: iocontrol MDC %s on MDT"
                                               " idx %d cmd %x: err = %d\n",
-                                              tgt->ltd_uuid.uuid, i, cmd, err);
+                                              tgt->ltd_uuid.uuid,
+                                              tgt->ltd_index, cmd, err);
                                        if (!rc)
                                                rc = err;
                                }
                        } else
                                set = 1;
-                }
-                if (!set && !rc)
-                        rc = -EIO;
-        }
-        RETURN(rc);
-}
-
-/**
- * This is _inode_ placement policy function (not name).
- */
-static int lmv_placement_policy(struct obd_device *obd,
-                               struct md_op_data *op_data, u32 *mds)
-{
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       ENTRY;
-
-       LASSERT(mds != NULL);
-
-       if (lmv->desc.ld_tgt_count == 1) {
-               *mds = 0;
-               RETURN(0);
-       }
-
-       if (op_data->op_default_stripe_offset != -1) {
-               *mds = op_data->op_default_stripe_offset;
-               RETURN(0);
-       }
-
-       /**
-        * If stripe_offset is provided during setdirstripe
-        * (setdirstripe -i xx), xx MDS will be choosen.
-        */
-       if (op_data->op_cli_flags & CLI_SET_MEA && op_data->op_data != NULL) {
-               struct lmv_user_md *lum;
-
-               lum = op_data->op_data;
-
-               if (le32_to_cpu(lum->lum_stripe_offset) != (__u32)-1) {
-                       *mds = le32_to_cpu(lum->lum_stripe_offset);
-               } else {
-                       /* -1 means default, which will be in the same MDT with
-                        * the stripe */
-                       *mds = op_data->op_mds;
-                       lum->lum_stripe_offset = cpu_to_le32(op_data->op_mds);
                }
-       } else {
-               /* Allocate new fid on target according to operation type and
-                * parent home mds. */
-               *mds = op_data->op_mds;
+               if (!set && !rc)
+                       rc = -EIO;
        }
-
-       RETURN(0);
+       RETURN(rc);
 }
 
-int __lmv_fid_alloc(struct lmv_obd *lmv, struct lu_fid *fid, u32 mds)
+int lmv_fid_alloc(const struct lu_env *env, struct obd_export *exp,
+                 struct lu_fid *fid, struct md_op_data *op_data)
 {
-       struct lmv_tgt_desc     *tgt;
-       int                      rc;
+       struct obd_device *obd = class_exp2obd(exp);
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
        ENTRY;
 
-       tgt = lmv_get_target(lmv, mds, NULL);
-       if (IS_ERR(tgt))
-               RETURN(PTR_ERR(tgt));
+       LASSERT(op_data);
+       LASSERT(fid);
+
+       tgt = lmv_tgt(lmv, op_data->op_mds);
+       if (!tgt)
+               RETURN(-ENODEV);
+
+       if (!tgt->ltd_active || !tgt->ltd_exp)
+               RETURN(-ENODEV);
 
        /*
         * New seq alloc and FLD setup should be atomic. Otherwise we may find
         * on server that seq in new allocated fid is not yet known.
         */
        mutex_lock(&tgt->ltd_fid_mutex);
-
-       if (tgt->ltd_active == 0 || tgt->ltd_exp == NULL)
-               GOTO(out, rc = -ENODEV);
-
-       /*
-        * Asking underlying tgt layer to allocate new fid.
-        */
        rc = obd_fid_alloc(NULL, tgt->ltd_exp, fid, NULL);
+       mutex_unlock(&tgt->ltd_fid_mutex);
        if (rc > 0) {
                LASSERT(fid_is_sane(fid));
                rc = 0;
        }
 
-        EXIT;
-out:
-       mutex_unlock(&tgt->ltd_fid_mutex);
-        return rc;
-}
-
-int lmv_fid_alloc(const struct lu_env *env, struct obd_export *exp,
-                 struct lu_fid *fid, struct md_op_data *op_data)
-{
-        struct obd_device     *obd = class_exp2obd(exp);
-        struct lmv_obd        *lmv = &obd->u.lmv;
-       u32                    mds = 0;
-        int                    rc;
-        ENTRY;
-
-        LASSERT(op_data != NULL);
-        LASSERT(fid != NULL);
-
-        rc = lmv_placement_policy(obd, op_data, &mds);
-        if (rc) {
-                CERROR("Can't get target for allocating fid, "
-                       "rc %d\n", rc);
-                RETURN(rc);
-        }
-
-        rc = __lmv_fid_alloc(lmv, fid, mds);
-        if (rc) {
-                CERROR("Can't alloc new fid, rc %d\n", rc);
-                RETURN(rc);
-        }
-
-        RETURN(rc);
+       RETURN(rc);
 }
 
 static int lmv_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 {
-       struct lmv_obd  *lmv = &obd->u.lmv;
+       struct lmv_obd *lmv = &obd->u.lmv;
        struct lmv_desc *desc;
-       int             rc;
-       ENTRY;
+       struct lnet_process_id lnet_id;
+       int i = 0;
+       int rc;
 
-        if (LUSTRE_CFG_BUFLEN(lcfg, 1) < 1) {
-                CERROR("LMV setup requires a descriptor\n");
-                RETURN(-EINVAL);
-        }
+       ENTRY;
 
-        desc = (struct lmv_desc *)lustre_cfg_buf(lcfg, 1);
-        if (sizeof(*desc) > LUSTRE_CFG_BUFLEN(lcfg, 1)) {
-                CERROR("Lmv descriptor size wrong: %d > %d\n",
-                       (int)sizeof(*desc), LUSTRE_CFG_BUFLEN(lcfg, 1));
-                RETURN(-EINVAL);
-        }
+       if (LUSTRE_CFG_BUFLEN(lcfg, 1) < 1) {
+               CERROR("LMV setup requires a descriptor\n");
+               RETURN(-EINVAL);
+       }
 
-       lmv->tgts_size = 32U;
-       OBD_ALLOC(lmv->tgts, sizeof(*lmv->tgts) * lmv->tgts_size);
-       if (lmv->tgts == NULL)
-               RETURN(-ENOMEM);
+       desc = (struct lmv_desc *)lustre_cfg_buf(lcfg, 1);
+       if (sizeof(*desc) > LUSTRE_CFG_BUFLEN(lcfg, 1)) {
+               CERROR("Lmv descriptor size wrong: %d > %d\n",
+                      (int)sizeof(*desc), LUSTRE_CFG_BUFLEN(lcfg, 1));
+               RETURN(-EINVAL);
+       }
 
-       obd_str2uuid(&lmv->desc.ld_uuid, desc->ld_uuid.uuid);
-       lmv->desc.ld_tgt_count = 0;
-       lmv->desc.ld_active_tgt_count = 0;
+       obd_str2uuid(&lmv->lmv_mdt_descs.ltd_lmv_desc.ld_uuid,
+                    desc->ld_uuid.uuid);
+       lmv->lmv_mdt_descs.ltd_lmv_desc.ld_tgt_count = 0;
+       lmv->lmv_mdt_descs.ltd_lmv_desc.ld_active_tgt_count = 0;
+       lmv->lmv_mdt_descs.ltd_lmv_desc.ld_qos_maxage =
+               LMV_DESC_QOS_MAXAGE_DEFAULT;
        lmv->max_def_easize = 0;
        lmv->max_easize = 0;
 
        spin_lock_init(&lmv->lmv_lock);
-       mutex_init(&lmv->lmv_init_mutex);
-
-#ifdef CONFIG_PROC_FS
-       obd->obd_vars = lprocfs_lmv_obd_vars;
-       lprocfs_obd_setup(obd);
-       lprocfs_alloc_md_stats(obd, 0);
-       rc = lprocfs_seq_create(obd->obd_proc_entry, "target_obd",
-                               0444, &lmv_proc_target_fops, obd);
-       if (rc)
-               CWARN("%s: error adding LMV target_obd file: rc = %d\n",
-                     obd->obd_name, rc);
-#endif
-       rc = fld_client_init(&lmv->lmv_fld, obd->obd_name,
-                            LUSTRE_CLI_FLD_HASH_DHT);
-       if (rc) {
-               CERROR("Can't init FLD, err %d\n", rc);
-               GOTO(out, rc);
+
+       /*
+        * initialize rr_index to lower 32bit of netid, so that client
+        * can distribute subdirs evenly from the beginning.
+        */
+       while (LNetGetId(i++, &lnet_id) != -ENOENT) {
+               if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND) {
+                       lmv->lmv_qos_rr_index = (u32)lnet_id.nid;
+                       break;
+               }
        }
 
-        RETURN(0);
+       rc = lmv_tunables_init(obd);
+       if (rc)
+               CWARN("%s: error adding LMV sysfs/debugfs files: rc = %d\n",
+                     obd->obd_name, rc);
 
-out:
-        return rc;
+       rc = fld_client_init(&lmv->lmv_fld, obd->obd_name,
+                            LUSTRE_CLI_FLD_HASH_DHT);
+       if (rc)
+               CERROR("Can't init FLD, err %d\n", rc);
+
+       rc = lu_tgt_descs_init(&lmv->lmv_mdt_descs, true);
+       if (rc)
+               CWARN("%s: error initialize target table: rc = %d\n",
+                     obd->obd_name, rc);
+
+       RETURN(rc);
 }
 
 static int lmv_cleanup(struct obd_device *obd)
 {
-       struct lmv_obd   *lmv = &obd->u.lmv;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lu_tgt_desc *tgt;
+       struct lu_tgt_desc *tmp;
+
        ENTRY;
 
        fld_client_fini(&lmv->lmv_fld);
-       if (lmv->tgts != NULL) {
-               int i;
-               for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-                       if (lmv->tgts[i] == NULL)
-                               continue;
-                       lmv_del_target(lmv, i);
-               }
-               OBD_FREE(lmv->tgts, sizeof(*lmv->tgts) * lmv->tgts_size);
-               lmv->tgts_size = 0;
-       }
+       lmv_foreach_tgt_safe(lmv, tgt, tmp)
+               lmv_del_target(lmv, tgt);
+       lu_tgt_descs_fini(&lmv->lmv_mdt_descs);
+
        RETURN(0);
 }
 
@@ -1380,319 +1200,640 @@ out:
        RETURN(rc);
 }
 
+static int lmv_select_statfs_mdt(struct lmv_obd *lmv, __u32 flags)
+{
+       int i;
+
+       if (flags & OBD_STATFS_FOR_MDT0)
+               return 0;
+
+       if (lmv->lmv_statfs_start || lmv->lmv_mdt_count == 1)
+               return lmv->lmv_statfs_start;
+
+       /* choose initial MDT for this client */
+       for (i = 0;; i++) {
+               struct lnet_process_id lnet_id;
+               if (LNetGetId(i, &lnet_id) == -ENOENT)
+                       break;
+
+               if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND) {
+                       /* We dont need a full 64-bit modulus, just enough
+                        * to distribute the requests across MDTs evenly.
+                        */
+                       lmv->lmv_statfs_start = (u32)lnet_id.nid %
+                                               lmv->lmv_mdt_count;
+                       break;
+               }
+       }
+
+       return lmv->lmv_statfs_start;
+}
+
 static int lmv_statfs(const struct lu_env *env, struct obd_export *exp,
-                      struct obd_statfs *osfs, __u64 max_age, __u32 flags)
+                     struct obd_statfs *osfs, time64_t max_age, __u32 flags)
 {
-       struct obd_device       *obd = class_exp2obd(exp);
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct obd_statfs       *temp;
-       int                      rc = 0;
-       __u32                    i;
+       struct obd_device *obd = class_exp2obd(exp);
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct obd_statfs *temp;
+       struct lu_tgt_desc *tgt;
+       __u32 i;
+       __u32 idx;
+       int rc = 0;
+
        ENTRY;
 
-        OBD_ALLOC(temp, sizeof(*temp));
-        if (temp == NULL)
-                RETURN(-ENOMEM);
+       OBD_ALLOC(temp, sizeof(*temp));
+       if (temp == NULL)
+               RETURN(-ENOMEM);
+
+       /* distribute statfs among MDTs */
+       idx = lmv_select_statfs_mdt(lmv, flags);
 
-        for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
+       for (i = 0; i < lmv->lmv_mdt_descs.ltd_tgts_size; i++, idx++) {
+               idx = idx % lmv->lmv_mdt_descs.ltd_tgts_size;
+               tgt = lmv_tgt(lmv, idx);
+               if (!tgt || !tgt->ltd_exp)
                        continue;
 
-               rc = obd_statfs(env, lmv->tgts[i]->ltd_exp, temp,
-                               max_age, flags);
+               rc = obd_statfs(env, tgt->ltd_exp, temp, max_age, flags);
                if (rc) {
-                       CERROR("can't stat MDS #%d (%s), error %d\n", i,
-                              lmv->tgts[i]->ltd_exp->exp_obd->obd_name,
-                              rc);
+                       CERROR("%s: can't stat MDS #%d: rc = %d\n",
+                              tgt->ltd_exp->exp_obd->obd_name, i, rc);
                        GOTO(out_free_temp, rc);
                }
 
+               if (temp->os_state & OS_STATE_SUM ||
+                   flags == OBD_STATFS_FOR_MDT0) {
+                       /* reset to the last aggregated values
+                        * and don't sum with non-aggrated data */
+                       /* If the statfs is from mount, it needs to retrieve
+                        * necessary information from MDT0. i.e. mount does
+                        * not need the merged osfs from all of MDT. Also
+                        * clients can be mounted as long as MDT0 is in
+                        * service */
+                       *osfs = *temp;
+                       break;
+               }
+
                if (i == 0) {
                        *osfs = *temp;
-                       /* If the statfs is from mount, it will needs
-                        * retrieve necessary information from MDT0.
-                        * i.e. mount does not need the merged osfs
-                        * from all of MDT.
-                        * And also clients can be mounted as long as
-                        * MDT0 is in service*/
-                       if (flags & OBD_STATFS_FOR_MDT0)
-                               GOTO(out_free_temp, rc);
-                } else {
-                        osfs->os_bavail += temp->os_bavail;
-                        osfs->os_blocks += temp->os_blocks;
-                        osfs->os_ffree += temp->os_ffree;
-                        osfs->os_files += temp->os_files;
-                }
-        }
+               } else {
+                       osfs->os_bavail += temp->os_bavail;
+                       osfs->os_blocks += temp->os_blocks;
+                       osfs->os_ffree += temp->os_ffree;
+                       osfs->os_files += temp->os_files;
+                       osfs->os_granted += temp->os_granted;
+               }
+       }
 
-        EXIT;
+       EXIT;
 out_free_temp:
-        OBD_FREE(temp, sizeof(*temp));
-        return rc;
+       OBD_FREE(temp, sizeof(*temp));
+       return rc;
+}
+
+static int lmv_statfs_update(void *cookie, int rc)
+{
+       struct obd_info *oinfo = cookie;
+       struct obd_device *obd = oinfo->oi_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt = oinfo->oi_tgt;
+       struct obd_statfs *osfs = oinfo->oi_osfs;
+
+       /*
+        * NB: don't deactivate TGT upon error, because we may not trigger async
+        * statfs any longer, then there is no chance to activate TGT.
+        */
+       if (!rc) {
+               spin_lock(&lmv->lmv_lock);
+               tgt->ltd_statfs = *osfs;
+               tgt->ltd_statfs_age = ktime_get_seconds();
+               spin_unlock(&lmv->lmv_lock);
+               lmv->lmv_qos.lq_dirty = 1;
+       }
+
+       return rc;
+}
+
+/* update tgt statfs async if it's ld_qos_maxage old */
+int lmv_statfs_check_update(struct obd_device *obd, struct lmv_tgt_desc *tgt)
+{
+       struct obd_info oinfo = {
+               .oi_obd = obd,
+               .oi_tgt = tgt,
+               .oi_cb_up = lmv_statfs_update,
+       };
+       int rc;
+
+       if (ktime_get_seconds() - tgt->ltd_statfs_age <
+           obd->u.lmv.lmv_mdt_descs.ltd_lmv_desc.ld_qos_maxage)
+               return 0;
+
+       rc = obd_statfs_async(tgt->ltd_exp, &oinfo, 0, NULL);
+
+       return rc;
 }
 
 static int lmv_get_root(struct obd_export *exp, const char *fileset,
                        struct lu_fid *fid)
 {
-        struct obd_device    *obd = exp->exp_obd;
-        struct lmv_obd       *lmv = &obd->u.lmv;
-        int                   rc;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lu_tgt_desc *tgt = lmv_tgt(lmv, 0);
+       int rc;
+
+       ENTRY;
+
+       if (!tgt)
+               RETURN(-ENODEV);
 
-       rc = md_get_root(lmv->tgts[0]->ltd_exp, fileset, fid);
+       rc = md_get_root(tgt->ltd_exp, fileset, fid);
        RETURN(rc);
 }
 
 static int lmv_getxattr(struct obd_export *exp, const struct lu_fid *fid,
-                       u64 valid, const char *name,
-                       const char *input, int input_size, int output_size,
-                       int flags, struct ptlrpc_request **request)
+                       u64 obd_md_valid, const char *name, size_t buf_size,
+                       struct ptlrpc_request **req)
 {
-        struct obd_device      *obd = exp->exp_obd;
-        struct lmv_obd         *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc    *tgt;
-        int                     rc;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
 
-        tgt = lmv_find_target(lmv, fid);
-        if (IS_ERR(tgt))
-                RETURN(PTR_ERR(tgt));
+       ENTRY;
 
-       rc = md_getxattr(tgt->ltd_exp, fid, valid, name, input,
-                        input_size, output_size, flags, request);
+       tgt = lmv_fid2tgt(lmv, fid);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
+
+       rc = md_getxattr(tgt->ltd_exp, fid, obd_md_valid, name, buf_size, req);
 
        RETURN(rc);
 }
 
 static int lmv_setxattr(struct obd_export *exp, const struct lu_fid *fid,
-                       u64 valid, const char *name,
-                       const char *input, int input_size, int output_size,
-                       int flags, __u32 suppgid,
-                       struct ptlrpc_request **request)
+                       u64 obd_md_valid, const char *name,
+                       const void *value, size_t value_size,
+                       unsigned int xattr_flags, u32 suppgid,
+                       struct ptlrpc_request **req)
 {
-        struct obd_device      *obd = exp->exp_obd;
-        struct lmv_obd         *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc    *tgt;
-        int                     rc;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
 
-        tgt = lmv_find_target(lmv, fid);
-        if (IS_ERR(tgt))
-                RETURN(PTR_ERR(tgt));
+       ENTRY;
+
+       tgt = lmv_fid2tgt(lmv, fid);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
 
-       rc = md_setxattr(tgt->ltd_exp, fid, valid, name, input,
-                        input_size, output_size, flags, suppgid,
-                        request);
+       rc = md_setxattr(tgt->ltd_exp, fid, obd_md_valid, name,
+                        value, value_size, xattr_flags, suppgid, req);
 
        RETURN(rc);
 }
 
 static int lmv_getattr(struct obd_export *exp, struct md_op_data *op_data,
-                       struct ptlrpc_request **request)
+                      struct ptlrpc_request **request)
 {
-        struct obd_device       *obd = exp->exp_obd;
-        struct lmv_obd          *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc     *tgt;
-        int                      rc;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
 
-        tgt = lmv_find_target(lmv, &op_data->op_fid1);
-        if (IS_ERR(tgt))
-                RETURN(PTR_ERR(tgt));
+       ENTRY;
+
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
 
        if (op_data->op_flags & MF_GET_MDT_IDX) {
-               op_data->op_mds = tgt->ltd_idx;
+               op_data->op_mds = tgt->ltd_index;
                RETURN(0);
        }
 
-        rc = md_getattr(tgt->ltd_exp, op_data, request);
+       rc = md_getattr(tgt->ltd_exp, op_data, request);
 
-        RETURN(rc);
+       RETURN(rc);
 }
 
 static int lmv_null_inode(struct obd_export *exp, const struct lu_fid *fid)
 {
-        struct obd_device   *obd = exp->exp_obd;
-        struct lmv_obd      *lmv = &obd->u.lmv;
-       __u32                i;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lu_tgt_desc *tgt;
 
-        CDEBUG(D_INODE, "CBDATA for "DFID"\n", PFID(fid));
+       ENTRY;
+
+       CDEBUG(D_INODE, "CBDATA for "DFID"\n", PFID(fid));
 
        /*
         * With DNE every object can have two locks in different namespaces:
         * lookup lock in space of MDT storing direntry and update/open lock in
         * space of MDT storing inode.
         */
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               if (lmv->tgts[i] == NULL || lmv->tgts[i]->ltd_exp == NULL)
-                       continue;
-               md_null_inode(lmv->tgts[i]->ltd_exp, fid);
-       }
+       lmv_foreach_connected_tgt(lmv, tgt)
+               md_null_inode(tgt->ltd_exp, fid);
 
        RETURN(0);
 }
 
 static int lmv_close(struct obd_export *exp, struct md_op_data *op_data,
-                     struct md_open_data *mod, struct ptlrpc_request **request)
+                    struct md_open_data *mod, struct ptlrpc_request **request)
 {
-        struct obd_device     *obd = exp->exp_obd;
-        struct lmv_obd        *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc   *tgt;
-        int                    rc;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
 
-        tgt = lmv_find_target(lmv, &op_data->op_fid1);
-        if (IS_ERR(tgt))
-                RETURN(PTR_ERR(tgt));
+       ENTRY;
+
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
 
-        CDEBUG(D_INODE, "CLOSE "DFID"\n", PFID(&op_data->op_fid1));
-        rc = md_close(tgt->ltd_exp, op_data, mod, request);
-        RETURN(rc);
+       CDEBUG(D_INODE, "CLOSE "DFID"\n", PFID(&op_data->op_fid1));
+       rc = md_close(tgt->ltd_exp, op_data, mod, request);
+       RETURN(rc);
 }
 
-/**
- * Choosing the MDT by name or FID in @op_data.
- * For non-striped directory, it will locate MDT by fid.
- * For striped-directory, it will locate MDT by name. And also
- * it will reset op_fid1 with the FID of the choosen stripe.
- **/
-struct lmv_tgt_desc *
-lmv_locate_target_for_name(struct lmv_obd *lmv, struct lmv_stripe_md *lsm,
-                          const char *name, int namelen, struct lu_fid *fid,
-                          u32 *mds)
+static struct lu_tgt_desc *lmv_locate_tgt_qos(struct lmv_obd *lmv, __u32 *mdt)
+{
+       struct lu_tgt_desc *tgt;
+       __u64 total_weight = 0;
+       __u64 cur_weight = 0;
+       __u64 rand;
+       int rc;
+
+       ENTRY;
+
+       if (!ltd_qos_is_usable(&lmv->lmv_mdt_descs))
+               RETURN(ERR_PTR(-EAGAIN));
+
+       down_write(&lmv->lmv_qos.lq_rw_sem);
+
+       if (!ltd_qos_is_usable(&lmv->lmv_mdt_descs))
+               GOTO(unlock, tgt = ERR_PTR(-EAGAIN));
+
+       rc = ltd_qos_penalties_calc(&lmv->lmv_mdt_descs);
+       if (rc)
+               GOTO(unlock, tgt = ERR_PTR(rc));
+
+       lmv_foreach_tgt(lmv, tgt) {
+               tgt->ltd_qos.ltq_usable = 0;
+               if (!tgt->ltd_exp || !tgt->ltd_active)
+                       continue;
+
+               tgt->ltd_qos.ltq_usable = 1;
+               lu_tgt_qos_weight_calc(tgt);
+               total_weight += tgt->ltd_qos.ltq_weight;
+       }
+
+       rand = lu_prandom_u64_max(total_weight);
+
+       lmv_foreach_connected_tgt(lmv, tgt) {
+               if (!tgt->ltd_qos.ltq_usable)
+                       continue;
+
+               cur_weight += tgt->ltd_qos.ltq_weight;
+               if (cur_weight < rand)
+                       continue;
+
+               *mdt = tgt->ltd_index;
+               ltd_qos_update(&lmv->lmv_mdt_descs, tgt, &total_weight);
+               GOTO(unlock, rc = 0);
+       }
+
+       /* no proper target found */
+       GOTO(unlock, tgt = ERR_PTR(-EAGAIN));
+unlock:
+       up_write(&lmv->lmv_qos.lq_rw_sem);
+
+       return tgt;
+}
+
+static struct lu_tgt_desc *lmv_locate_tgt_rr(struct lmv_obd *lmv, __u32 *mdt)
+{
+       struct lu_tgt_desc *tgt;
+       int i;
+       int index;
+
+       ENTRY;
+
+       spin_lock(&lmv->lmv_qos.lq_rr.lqr_alloc);
+       for (i = 0; i < lmv->lmv_mdt_descs.ltd_tgts_size; i++) {
+               index = (i + lmv->lmv_qos_rr_index) %
+                       lmv->lmv_mdt_descs.ltd_tgts_size;
+               tgt = lmv_tgt(lmv, index);
+               if (!tgt || !tgt->ltd_exp || !tgt->ltd_active)
+                       continue;
+
+               *mdt = tgt->ltd_index;
+               lmv->lmv_qos_rr_index = (*mdt + 1) %
+                                       lmv->lmv_mdt_descs.ltd_tgts_size;
+               spin_unlock(&lmv->lmv_qos.lq_rr.lqr_alloc);
+
+               RETURN(tgt);
+       }
+       spin_unlock(&lmv->lmv_qos.lq_rr.lqr_alloc);
+
+       RETURN(ERR_PTR(-ENODEV));
+}
+
+static struct lmv_tgt_desc *
+lmv_locate_tgt_by_name(struct lmv_obd *lmv, struct lmv_stripe_md *lsm,
+                      const char *name, int namelen, struct lu_fid *fid,
+                      __u32 *mds, bool post_migrate)
 {
-       struct lmv_tgt_desc     *tgt;
-       const struct lmv_oinfo  *oinfo;
+       struct lmv_tgt_desc *tgt;
+       const struct lmv_oinfo *oinfo;
+
+       if (!lmv_dir_striped(lsm) || !namelen) {
+               tgt = lmv_fid2tgt(lmv, fid);
+               if (IS_ERR(tgt))
+                       return tgt;
+
+               *mds = tgt->ltd_index;
+               return tgt;
+       }
 
        if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_NAME_HASH)) {
                if (cfs_fail_val >= lsm->lsm_md_stripe_count)
-                       RETURN(ERR_PTR(-EBADF));
+                       return ERR_PTR(-EBADF);
                oinfo = &lsm->lsm_md_oinfo[cfs_fail_val];
        } else {
-               oinfo = lsm_name_to_stripe_info(lsm, name, namelen);
+               oinfo = lsm_name_to_stripe_info(lsm, name, namelen,
+                                               post_migrate);
                if (IS_ERR(oinfo))
-                       RETURN(ERR_CAST(oinfo));
+                       return ERR_CAST(oinfo);
        }
 
-       if (fid != NULL)
-               *fid = oinfo->lmo_fid;
-       if (mds != NULL)
-               *mds = oinfo->lmo_mds;
+       *fid = oinfo->lmo_fid;
+       *mds = oinfo->lmo_mds;
+       tgt = lmv_tgt(lmv, oinfo->lmo_mds);
 
-       tgt = lmv_get_target(lmv, oinfo->lmo_mds, NULL);
+       CDEBUG(D_INODE, "locate MDT %u parent "DFID"\n", *mds, PFID(fid));
 
-       CDEBUG(D_INFO, "locate on mds %u "DFID"\n", oinfo->lmo_mds,
-              PFID(&oinfo->lmo_fid));
-       return tgt;
+       return tgt ? tgt : ERR_PTR(-ENODEV);
 }
 
 /**
- * Locate mds by fid or name
+ * Locate MDT of op_data->op_fid1
  *
- * For striped directory (lsm != NULL), it will locate the stripe
- * by name hash (see lsm_name_to_stripe_info()). Note: if the hash_type
- * is unknown, it will return -EBADFD, and lmv_intent_lookup might need
- * walk through all of stripes to locate the entry.
+ * For striped directory, it will locate the stripe by name hash, if hash_type
+ * is unknown, it will return the stripe specified by 'op_data->op_stripe_index'
+ * which is set outside, and if dir is migrating, 'op_data->op_post_migrate'
+ * indicates whether old or new layout is used to locate.
+ *
+ * For plain direcotry, it just locate the MDT of op_data->op_fid1.
  *
- * For normal direcotry, it will locate MDS by FID directly.
  * \param[in] lmv      LMV device
  * \param[in] op_data  client MD stack parameters, name, namelen
  *                      mds_num etc.
- * \param[in] fid      object FID used to locate MDS.
  *
  * retval              pointer to the lmv_tgt_desc if succeed.
  *                      ERR_PTR(errno) if failed.
  */
-struct lmv_tgt_desc*
-lmv_locate_mds(struct lmv_obd *lmv, struct md_op_data *op_data,
-              struct lu_fid *fid)
+struct lmv_tgt_desc *
+lmv_locate_tgt(struct lmv_obd *lmv, struct md_op_data *op_data)
 {
-       struct lmv_stripe_md    *lsm = op_data->op_mea1;
-       struct lmv_tgt_desc     *tgt;
+       struct lmv_stripe_md *lsm = op_data->op_mea1;
+       struct lmv_oinfo *oinfo;
+       struct lmv_tgt_desc *tgt;
+
+       if (lmv_dir_foreign(lsm))
+               return ERR_PTR(-ENODATA);
 
        /* During creating VOLATILE file, it should honor the mdt
         * index if the file under striped dir is being restored, see
         * ct_restore(). */
        if (op_data->op_bias & MDS_CREATE_VOLATILE &&
-           (int)op_data->op_mds != -1) {
-               int i;
-               tgt = lmv_get_target(lmv, op_data->op_mds, NULL);
-               if (IS_ERR(tgt))
-                       return tgt;
+           op_data->op_mds != LMV_OFFSET_DEFAULT) {
+               tgt = lmv_tgt(lmv, op_data->op_mds);
+               if (!tgt)
+                       return ERR_PTR(-ENODEV);
+
+               if (lmv_dir_striped(lsm)) {
+                       int i;
 
-               if (lsm != NULL) {
                        /* refill the right parent fid */
                        for (i = 0; i < lsm->lsm_md_stripe_count; i++) {
-                               struct lmv_oinfo *oinfo;
-
                                oinfo = &lsm->lsm_md_oinfo[i];
                                if (oinfo->lmo_mds == op_data->op_mds) {
-                                       *fid = oinfo->lmo_fid;
+                                       op_data->op_fid1 = oinfo->lmo_fid;
                                        break;
                                }
                        }
 
                        if (i == lsm->lsm_md_stripe_count)
-                               *fid = lsm->lsm_md_oinfo[0].lmo_fid;
+                               op_data->op_fid1 = lsm->lsm_md_oinfo[0].lmo_fid;
                }
+       } else if (lmv_dir_bad_hash(lsm)) {
+               LASSERT(op_data->op_stripe_index < lsm->lsm_md_stripe_count);
+               oinfo = &lsm->lsm_md_oinfo[op_data->op_stripe_index];
 
-               return tgt;
+               op_data->op_fid1 = oinfo->lmo_fid;
+               op_data->op_mds = oinfo->lmo_mds;
+               tgt = lmv_tgt(lmv, oinfo->lmo_mds);
+               if (!tgt)
+                       return ERR_PTR(-ENODEV);
+       } else {
+               tgt = lmv_locate_tgt_by_name(lmv, op_data->op_mea1,
+                               op_data->op_name, op_data->op_namelen,
+                               &op_data->op_fid1, &op_data->op_mds,
+                               op_data->op_post_migrate);
        }
 
-       if (lsm == NULL || op_data->op_namelen == 0) {
-               tgt = lmv_find_target(lmv, fid);
+       return tgt;
+}
+
+/* Locate MDT of op_data->op_fid2 for link/rename */
+static struct lmv_tgt_desc *
+lmv_locate_tgt2(struct lmv_obd *lmv, struct md_op_data *op_data)
+{
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
+       LASSERT(op_data->op_name);
+       if (lmv_dir_migrating(op_data->op_mea2)) {
+               struct lu_fid fid1 = op_data->op_fid1;
+               struct lmv_stripe_md *lsm1 = op_data->op_mea1;
+               struct ptlrpc_request *request = NULL;
+
+               /*
+                * avoid creating new file under old layout of migrating
+                * directory, check it here.
+                */
+               tgt = lmv_locate_tgt_by_name(lmv, op_data->op_mea2,
+                               op_data->op_name, op_data->op_namelen,
+                               &op_data->op_fid2, &op_data->op_mds, false);
                if (IS_ERR(tgt))
-                       return tgt;
+                       RETURN(tgt);
+
+               op_data->op_fid1 = op_data->op_fid2;
+               op_data->op_mea1 = op_data->op_mea2;
+               rc = md_getattr_name(tgt->ltd_exp, op_data, &request);
+               op_data->op_fid1 = fid1;
+               op_data->op_mea1 = lsm1;
+               if (!rc) {
+                       ptlrpc_req_finished(request);
+                       RETURN(ERR_PTR(-EEXIST));
+               }
 
-               op_data->op_mds = tgt->ltd_idx;
-               return tgt;
+               if (rc != -ENOENT)
+                       RETURN(ERR_PTR(rc));
        }
 
-       return lmv_locate_target_for_name(lmv, lsm, op_data->op_name,
-                                         op_data->op_namelen, fid,
-                                         &op_data->op_mds);
+       return lmv_locate_tgt_by_name(lmv, op_data->op_mea2, op_data->op_name,
+                               op_data->op_namelen, &op_data->op_fid2,
+                               &op_data->op_mds, true);
+}
+
+int lmv_migrate_existence_check(struct lmv_obd *lmv, struct md_op_data *op_data)
+{
+       struct lu_tgt_desc *tgt;
+       struct ptlrpc_request *request;
+       int rc;
+
+       LASSERT(lmv_dir_migrating(op_data->op_mea1));
+
+       tgt = lmv_locate_tgt(lmv, op_data);
+       if (IS_ERR(tgt))
+               return PTR_ERR(tgt);
+
+       rc = md_getattr_name(tgt->ltd_exp, op_data, &request);
+       if (!rc) {
+               ptlrpc_req_finished(request);
+               return -EEXIST;
+       }
+
+       return rc;
+}
+
+/* mkdir by QoS in two cases:
+ * 1. 'lfs mkdir -i -1'
+ * 2. parent default LMV master_mdt_index is -1
+ *
+ * NB, mkdir by QoS only if parent is not striped, this is to avoid remote
+ * directories under striped directory.
+ */
+static inline bool lmv_op_qos_mkdir(const struct md_op_data *op_data)
+{
+       const struct lmv_stripe_md *lsm = op_data->op_default_mea1;
+       const struct lmv_user_md *lum = op_data->op_data;
+
+       if (op_data->op_code != LUSTRE_OPC_MKDIR)
+               return false;
+
+       if (lmv_dir_striped(op_data->op_mea1))
+               return false;
+
+       if (op_data->op_cli_flags & CLI_SET_MEA && lum &&
+           (le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC ||
+            le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC_SPECIFIC) &&
+           le32_to_cpu(lum->lum_stripe_offset) == LMV_OFFSET_DEFAULT)
+               return true;
+
+       if (lsm && lsm->lsm_md_master_mdt_index == LMV_OFFSET_DEFAULT)
+               return true;
+
+       return false;
+}
+
+/* 'lfs mkdir -i <specific_MDT>' */
+static inline bool lmv_op_user_specific_mkdir(const struct md_op_data *op_data)
+{
+       const struct lmv_user_md *lum = op_data->op_data;
+
+       return op_data->op_code == LUSTRE_OPC_MKDIR &&
+              op_data->op_cli_flags & CLI_SET_MEA && lum &&
+              (le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC ||
+               le32_to_cpu(lum->lum_magic) == LMV_USER_MAGIC_SPECIFIC) &&
+              le32_to_cpu(lum->lum_stripe_offset) != LMV_OFFSET_DEFAULT;
 }
 
+/* parent default LMV master_mdt_index is not -1. */
+static inline bool
+lmv_op_default_specific_mkdir(const struct md_op_data *op_data)
+{
+       return op_data->op_code == LUSTRE_OPC_MKDIR &&
+              op_data->op_default_mea1 &&
+              op_data->op_default_mea1->lsm_md_master_mdt_index !=
+                       LMV_OFFSET_DEFAULT;
+}
 int lmv_create(struct obd_export *exp, struct md_op_data *op_data,
                const void *data, size_t datalen, umode_t mode, uid_t uid,
                gid_t gid, cfs_cap_t cap_effective, __u64 rdev,
                struct ptlrpc_request **request)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt;
-       int                      rc;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
        ENTRY;
 
-       if (!lmv->desc.ld_active_tgt_count)
+       if (!lmv->lmv_mdt_descs.ltd_lmv_desc.ld_active_tgt_count)
                RETURN(-EIO);
 
-       tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+       if (lmv_dir_bad_hash(op_data->op_mea1))
+               RETURN(-EBADF);
+
+       if (lmv_dir_migrating(op_data->op_mea1)) {
+               /*
+                * if parent is migrating, create() needs to lookup existing
+                * name in both old and new layout, check old layout on client.
+                */
+               rc = lmv_migrate_existence_check(lmv, op_data);
+               if (rc != -ENOENT)
+                       RETURN(rc);
+
+               op_data->op_post_migrate = true;
+       }
+
+       tgt = lmv_locate_tgt(lmv, op_data);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
-       CDEBUG(D_INODE, "CREATE name '%.*s' on "DFID" -> mds #%x\n",
-               (int)op_data->op_namelen, op_data->op_name,
-               PFID(&op_data->op_fid1), op_data->op_mds);
+       if (lmv_op_qos_mkdir(op_data)) {
+               tgt = lmv_locate_tgt_qos(lmv, &op_data->op_mds);
+               if (tgt == ERR_PTR(-EAGAIN))
+                       tgt = lmv_locate_tgt_rr(lmv, &op_data->op_mds);
+               /*
+                * only update statfs after QoS mkdir, this means the cached
+                * statfs may be stale, and current mkdir may not follow QoS
+                * accurately, but it's not serious, and avoids periodic statfs
+                * when client doesn't mkdir by QoS.
+                */
+               if (!IS_ERR(tgt))
+                       lmv_statfs_check_update(obd, tgt);
+       } else if (lmv_op_user_specific_mkdir(op_data)) {
+               struct lmv_user_md *lum = op_data->op_data;
+
+               op_data->op_mds = le32_to_cpu(lum->lum_stripe_offset);
+               tgt = lmv_tgt(lmv, op_data->op_mds);
+               if (!tgt)
+                       RETURN(-ENODEV);
+       } else if (lmv_op_default_specific_mkdir(op_data)) {
+               op_data->op_mds =
+                       op_data->op_default_mea1->lsm_md_master_mdt_index;
+               tgt = lmv_tgt(lmv, op_data->op_mds);
+               if (!tgt)
+                       RETURN(-ENODEV);
+       }
+
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
 
        rc = lmv_fid_alloc(NULL, exp, &op_data->op_fid2, op_data);
        if (rc)
                RETURN(rc);
-       if (exp_connect_flags(exp) & OBD_CONNECT_DIR_STRIPE) {
-               /* Send the create request to the MDT where the object
-                * will be located */
-               tgt = lmv_find_target(lmv, &op_data->op_fid2);
-               if (IS_ERR(tgt))
-                       RETURN(PTR_ERR(tgt));
-
-               op_data->op_mds = tgt->ltd_idx;
-       } else {
-               CDEBUG(D_CONFIG, "Server doesn't support striped dirs\n");
-       }
 
-       CDEBUG(D_INODE, "CREATE obj "DFID" -> mds #%x\n",
-              PFID(&op_data->op_fid2), op_data->op_mds);
+       CDEBUG(D_INODE, "CREATE name '%.*s' "DFID" on "DFID" -> mds #%x\n",
+               (int)op_data->op_namelen, op_data->op_name,
+               PFID(&op_data->op_fid2), PFID(&op_data->op_fid1),
+               op_data->op_mds);
 
        op_data->op_flags |= MF_MDC_CANCEL_FID1;
        rc = md_create(tgt->ltd_exp, op_data, data, datalen, mode, uid, gid,
@@ -1710,20 +1851,21 @@ lmv_enqueue(struct obd_export *exp, struct ldlm_enqueue_info *einfo,
            const union ldlm_policy_data *policy, struct md_op_data *op_data,
            struct lustre_handle *lockh, __u64 extra_lock_flags)
 {
-       struct obd_device        *obd = exp->exp_obd;
-       struct lmv_obd           *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc      *tgt;
-       int                       rc;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
        ENTRY;
 
        CDEBUG(D_INODE, "ENQUEUE on "DFID"\n", PFID(&op_data->op_fid1));
 
-       tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
        CDEBUG(D_INODE, "ENQUEUE on "DFID" -> mds #%u\n",
-              PFID(&op_data->op_fid1), tgt->ltd_idx);
+              PFID(&op_data->op_fid1), tgt->ltd_index);
 
        rc = md_enqueue(tgt->ltd_exp, einfo, policy, op_data, lockh,
                        extra_lock_flags);
@@ -1731,52 +1873,50 @@ lmv_enqueue(struct obd_export *exp, struct ldlm_enqueue_info *einfo,
        RETURN(rc);
 }
 
-static int
+int
 lmv_getattr_name(struct obd_export *exp,struct md_op_data *op_data,
                 struct ptlrpc_request **preq)
 {
-       struct ptlrpc_request   *req = NULL;
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt;
-       struct mdt_body         *body;
-       int                      rc;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       struct mdt_body *body;
+       int rc;
+
        ENTRY;
 
-       tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+retry:
+       tgt = lmv_locate_tgt(lmv, op_data);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
        CDEBUG(D_INODE, "GETATTR_NAME for %*s on "DFID" -> mds #%d\n",
                (int)op_data->op_namelen, op_data->op_name,
-               PFID(&op_data->op_fid1), tgt->ltd_idx);
+               PFID(&op_data->op_fid1), tgt->ltd_index);
 
        rc = md_getattr_name(tgt->ltd_exp, op_data, preq);
-       if (rc != 0)
+       if (rc == -ENOENT && lmv_dir_retry_check_update(op_data)) {
+               ptlrpc_req_finished(*preq);
+               *preq = NULL;
+               goto retry;
+       }
+
+       if (rc)
                RETURN(rc);
 
        body = req_capsule_server_get(&(*preq)->rq_pill, &RMF_MDT_BODY);
        LASSERT(body != NULL);
 
        if (body->mbo_valid & OBD_MD_MDS) {
-               struct lu_fid rid = body->mbo_fid1;
-               CDEBUG(D_INODE, "Request attrs for "DFID"\n",
-                      PFID(&rid));
-
-               tgt = lmv_find_target(lmv, &rid);
-               if (IS_ERR(tgt)) {
-                       ptlrpc_req_finished(*preq);
-                       preq = NULL;
-                       RETURN(PTR_ERR(tgt));
-               }
-
-               op_data->op_fid1 = rid;
+               op_data->op_fid1 = body->mbo_fid1;
                op_data->op_valid |= OBD_MD_FLCROSSREF;
                op_data->op_namelen = 0;
                op_data->op_name = NULL;
-               rc = md_getattr_name(tgt->ltd_exp, op_data, &req);
+
                ptlrpc_req_finished(*preq);
-               *preq = req;
+               *preq = NULL;
+
+               goto retry;
        }
 
        RETURN(rc);
@@ -1803,12 +1943,12 @@ static int lmv_early_cancel(struct obd_export *exp, struct lmv_tgt_desc *tgt,
                RETURN(0);
 
        if (tgt == NULL) {
-               tgt = lmv_find_target(lmv, fid);
+               tgt = lmv_fid2tgt(lmv, fid);
                if (IS_ERR(tgt))
                        RETURN(PTR_ERR(tgt));
        }
 
-       if (tgt->ltd_idx != op_tgt) {
+       if (tgt->ltd_index != op_tgt) {
                CDEBUG(D_INODE, "EARLY_CANCEL on "DFID"\n", PFID(fid));
                policy.l_inodebits.bits = bits;
                rc = md_cancel_unused(tgt->ltd_exp, fid, &policy,
@@ -1846,19 +1986,8 @@ static int lmv_link(struct obd_export *exp, struct md_op_data *op_data,
        op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
        op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
        op_data->op_cap = cfs_curproc_cap_pack();
-       if (op_data->op_mea2 != NULL) {
-               struct lmv_stripe_md    *lsm = op_data->op_mea2;
-               const struct lmv_oinfo  *oinfo;
-
-               oinfo = lsm_name_to_stripe_info(lsm, op_data->op_name,
-                                               op_data->op_namelen);
-               if (IS_ERR(oinfo))
-                       RETURN(PTR_ERR(oinfo));
-
-               op_data->op_fid2 = oinfo->lmo_fid;
-       }
 
-       tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid2);
+       tgt = lmv_locate_tgt2(lmv, op_data);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
@@ -1866,7 +1995,7 @@ static int lmv_link(struct obd_export *exp, struct md_op_data *op_data,
         * Cancel UPDATE lock on child (fid1).
         */
        op_data->op_flags |= MF_MDC_CANCEL_FID2;
-       rc = lmv_early_cancel(exp, NULL, op_data, tgt->ltd_idx, LCK_EX,
+       rc = lmv_early_cancel(exp, NULL, op_data, tgt->ltd_index, LCK_EX,
                              MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID1);
        if (rc != 0)
                RETURN(rc);
@@ -1876,158 +2005,296 @@ static int lmv_link(struct obd_export *exp, struct md_op_data *op_data,
        RETURN(rc);
 }
 
-static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
-                     const char *old, size_t oldlen,
-                     const char *new, size_t newlen,
-                     struct ptlrpc_request **request)
+static int lmv_migrate(struct obd_export *exp, struct md_op_data *op_data,
+                       const char *name, size_t namelen,
+                       struct ptlrpc_request **request)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *src_tgt;
-       struct lmv_tgt_desc     *tgt_tgt;
-       struct obd_export       *target_exp;
-       struct mdt_body         *body;
-       int                     rc;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_stripe_md *lsm = op_data->op_mea1;
+       struct lmv_tgt_desc *parent_tgt;
+       struct lmv_tgt_desc *sp_tgt;
+       struct lmv_tgt_desc *tp_tgt = NULL;
+       struct lmv_tgt_desc *child_tgt;
+       struct lmv_tgt_desc *tgt;
+       struct lu_fid target_fid;
+       int rc;
+
        ENTRY;
 
-       LASSERT(oldlen != 0);
+       LASSERT(op_data->op_cli_flags & CLI_MIGRATE);
 
-       CDEBUG(D_INODE, "RENAME %.*s in "DFID":%d to %.*s in "DFID":%d\n",
-              (int)oldlen, old, PFID(&op_data->op_fid1),
-              op_data->op_mea1 ? op_data->op_mea1->lsm_md_stripe_count : 0,
-              (int)newlen, new, PFID(&op_data->op_fid2),
-              op_data->op_mea2 ? op_data->op_mea2->lsm_md_stripe_count : 0);
+       CDEBUG(D_INODE, "MIGRATE "DFID"/%.*s\n",
+              PFID(&op_data->op_fid1), (int)namelen, name);
 
        op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
        op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
        op_data->op_cap = cfs_curproc_cap_pack();
-       if (op_data->op_cli_flags & CLI_MIGRATE) {
-               LASSERTF(fid_is_sane(&op_data->op_fid3), "invalid FID "DFID"\n",
-                        PFID(&op_data->op_fid3));
-
-               if (op_data->op_mea1 != NULL) {
-                       struct lmv_stripe_md    *lsm = op_data->op_mea1;
-                       struct lmv_tgt_desc     *tmp;
-
-                       /* Fix the parent fid for striped dir */
-                       tmp = lmv_locate_target_for_name(lmv, lsm, old,
-                                                        oldlen,
-                                                        &op_data->op_fid1,
-                                                        NULL);
-                       if (IS_ERR(tmp))
-                               RETURN(PTR_ERR(tmp));
-               }
 
-               rc = lmv_fid_alloc(NULL, exp, &op_data->op_fid2, op_data);
-               if (rc != 0)
-                       RETURN(rc);
-
-               src_tgt = lmv_find_target(lmv, &op_data->op_fid3);
-               if (IS_ERR(src_tgt))
-                       RETURN(PTR_ERR(src_tgt));
+       parent_tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
+       if (IS_ERR(parent_tgt))
+               RETURN(PTR_ERR(parent_tgt));
 
-               target_exp = src_tgt->ltd_exp;
-       } else {
-               if (op_data->op_mea1 != NULL) {
-                       struct lmv_stripe_md    *lsm = op_data->op_mea1;
+       if (lmv_dir_striped(lsm)) {
+               __u32 hash_type = lsm->lsm_md_hash_type;
+               __u32 stripe_count = lsm->lsm_md_stripe_count;
 
-                       src_tgt = lmv_locate_target_for_name(lmv, lsm, old,
-                                                            oldlen,
-                                                            &op_data->op_fid1,
-                                                            &op_data->op_mds);
-               } else {
-                       src_tgt = lmv_find_target(lmv, &op_data->op_fid1);
+               /*
+                * old stripes are appended after new stripes for migrating
+                * directory.
+                */
+               if (lmv_dir_migrating(lsm)) {
+                       hash_type = lsm->lsm_md_migrate_hash;
+                       stripe_count -= lsm->lsm_md_migrate_offset;
                }
-               if (IS_ERR(src_tgt))
-                       RETURN(PTR_ERR(src_tgt));
 
+               rc = lmv_name_to_stripe_index(hash_type, stripe_count, name,
+                                             namelen);
+               if (rc < 0)
+                       RETURN(rc);
 
-               if (op_data->op_mea2 != NULL) {
-                       struct lmv_stripe_md    *lsm = op_data->op_mea2;
+               if (lmv_dir_migrating(lsm))
+                       rc += lsm->lsm_md_migrate_offset;
 
-                       tgt_tgt = lmv_locate_target_for_name(lmv, lsm, new,
-                                                            newlen,
-                                                            &op_data->op_fid2,
-                                                            &op_data->op_mds);
-               } else {
-                       tgt_tgt = lmv_find_target(lmv, &op_data->op_fid2);
+               /* save it in fid4 temporarily for early cancel */
+               op_data->op_fid4 = lsm->lsm_md_oinfo[rc].lmo_fid;
+               sp_tgt = lmv_tgt(lmv, lsm->lsm_md_oinfo[rc].lmo_mds);
+               if (!sp_tgt)
+                       RETURN(-ENODEV);
 
-               }
-               if (IS_ERR(tgt_tgt))
-                       RETURN(PTR_ERR(tgt_tgt));
+               /*
+                * if parent is being migrated too, fill op_fid2 with target
+                * stripe fid, otherwise the target stripe is not created yet.
+                */
+               if (lmv_dir_migrating(lsm)) {
+                       hash_type = lsm->lsm_md_hash_type &
+                                   ~LMV_HASH_FLAG_MIGRATION;
+                       stripe_count = lsm->lsm_md_migrate_offset;
+
+                       rc = lmv_name_to_stripe_index(hash_type, stripe_count,
+                                                     name, namelen);
+                       if (rc < 0)
+                               RETURN(rc);
 
-               target_exp = tgt_tgt->ltd_exp;
+                       op_data->op_fid2 = lsm->lsm_md_oinfo[rc].lmo_fid;
+                       tp_tgt = lmv_tgt(lmv, lsm->lsm_md_oinfo[rc].lmo_mds);
+                       if (!tp_tgt)
+                               RETURN(-ENODEV);
+               }
+       } else {
+               sp_tgt = parent_tgt;
        }
 
-       /*
-        * LOOKUP lock on src child (fid3) should also be cancelled for
-        * src_tgt in mdc_rename.
-        */
-       op_data->op_flags |= MF_MDC_CANCEL_FID1 | MF_MDC_CANCEL_FID3;
+       child_tgt = lmv_fid2tgt(lmv, &op_data->op_fid3);
+       if (IS_ERR(child_tgt))
+               RETURN(PTR_ERR(child_tgt));
 
-       /*
-        * Cancel UPDATE locks on tgt parent (fid2), tgt_tgt is its
-        * own target.
+       /* for directory, migrate to MDT specified by lum_stripe_offset;
+        * otherwise migrate to the target stripe of parent, but parent
+        * directory may have finished migration (normally current file too),
+        * allocate FID on MDT lum_stripe_offset, and server will check
+        * whether file was migrated already.
         */
-       rc = lmv_early_cancel(exp, NULL, op_data, src_tgt->ltd_idx,
-                             LCK_EX, MDS_INODELOCK_UPDATE,
-                             MF_MDC_CANCEL_FID2);
+       if (S_ISDIR(op_data->op_mode) || !tp_tgt) {
+               struct lmv_user_md *lum = op_data->op_data;
 
-       if (rc != 0)
+               op_data->op_mds = le32_to_cpu(lum->lum_stripe_offset);
+       } else  {
+               op_data->op_mds = tp_tgt->ltd_index;
+       }
+       rc = lmv_fid_alloc(NULL, exp, &target_fid, op_data);
+       if (rc)
                RETURN(rc);
+
        /*
-        * Cancel LOOKUP locks on source child (fid3) for parent tgt_tgt.
+        * for directory, send migrate request to the MDT where the object will
+        * be migrated to, because we can't create a striped directory remotely.
+        *
+        * otherwise, send to the MDT where source is located because regular
+        * file may open lease.
+        *
+        * NB. if MDT doesn't support DIR_MIGRATE, send to source MDT too for
+        * backward compatibility.
         */
-       if (fid_is_sane(&op_data->op_fid3)) {
-               struct lmv_tgt_desc *tgt;
-
-               tgt = lmv_find_target(lmv, &op_data->op_fid1);
+       if (S_ISDIR(op_data->op_mode) &&
+           (exp_connect_flags2(exp) & OBD_CONNECT2_DIR_MIGRATE)) {
+               tgt = lmv_fid2tgt(lmv, &target_fid);
                if (IS_ERR(tgt))
                        RETURN(PTR_ERR(tgt));
+       } else {
+               tgt = child_tgt;
+       }
 
-               /* Cancel LOOKUP lock on its parent */
-               rc = lmv_early_cancel(exp, tgt, op_data, src_tgt->ltd_idx,
-                                     LCK_EX, MDS_INODELOCK_LOOKUP,
-                                     MF_MDC_CANCEL_FID3);
-               if (rc != 0)
+       /* cancel UPDATE lock of parent master object */
+       rc = lmv_early_cancel(exp, parent_tgt, op_data, tgt->ltd_index, LCK_EX,
+                             MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID1);
+       if (rc)
+               RETURN(rc);
+
+       /* cancel UPDATE lock of source parent */
+       if (sp_tgt != parent_tgt) {
+               /*
+                * migrate RPC packs master object FID, because we can only pack
+                * two FIDs in reint RPC, but MDS needs to know both source
+                * parent and target parent, and it will obtain them from master
+                * FID and LMV, the other FID in RPC is kept for target.
+                *
+                * since this FID is not passed to MDC, cancel it anyway.
+                */
+               rc = lmv_early_cancel(exp, sp_tgt, op_data, -1, LCK_EX,
+                                     MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID4);
+               if (rc)
                        RETURN(rc);
 
-               rc = lmv_early_cancel(exp, NULL, op_data, src_tgt->ltd_idx,
-                                     LCK_EX, MDS_INODELOCK_FULL,
+               op_data->op_flags &= ~MF_MDC_CANCEL_FID4;
+       }
+       op_data->op_fid4 = target_fid;
+
+       /* cancel UPDATE locks of target parent */
+       rc = lmv_early_cancel(exp, tp_tgt, op_data, tgt->ltd_index, LCK_EX,
+                             MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID2);
+       if (rc)
+               RETURN(rc);
+
+       /* cancel LOOKUP lock of source if source is remote object */
+       if (child_tgt != sp_tgt) {
+               rc = lmv_early_cancel(exp, sp_tgt, op_data, tgt->ltd_index,
+                                     LCK_EX, MDS_INODELOCK_LOOKUP,
                                      MF_MDC_CANCEL_FID3);
-               if (rc != 0)
+               if (rc)
                        RETURN(rc);
        }
 
-retry_rename:
-       /*
-        * Cancel all the locks on tgt child (fid4).
-        */
+       /* cancel ELC locks of source */
+       rc = lmv_early_cancel(exp, child_tgt, op_data, tgt->ltd_index, LCK_EX,
+                             MDS_INODELOCK_ELC, MF_MDC_CANCEL_FID3);
+       if (rc)
+               RETURN(rc);
+
+       rc = md_rename(tgt->ltd_exp, op_data, name, namelen, NULL, 0, request);
+
+       RETURN(rc);
+}
+
+static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
+                     const char *old, size_t oldlen,
+                     const char *new, size_t newlen,
+                     struct ptlrpc_request **request)
+{
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *sp_tgt;
+       struct lmv_tgt_desc *tp_tgt = NULL;
+       struct lmv_tgt_desc *src_tgt = NULL;
+       struct lmv_tgt_desc *tgt;
+       struct mdt_body *body;
+       int rc;
+
+       ENTRY;
+
+       LASSERT(oldlen != 0);
+
+       if (op_data->op_cli_flags & CLI_MIGRATE) {
+               rc = lmv_migrate(exp, op_data, old, oldlen, request);
+               RETURN(rc);
+       }
+
+       op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
+       op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
+       op_data->op_cap = cfs_curproc_cap_pack();
+
+       op_data->op_name = new;
+       op_data->op_namelen = newlen;
+
+       tp_tgt = lmv_locate_tgt2(lmv, op_data);
+       if (IS_ERR(tp_tgt))
+               RETURN(PTR_ERR(tp_tgt));
+
+       /* Since the target child might be destroyed, and it might become
+        * orphan, and we can only check orphan on the local MDT right now, so
+        * we send rename request to the MDT where target child is located. If
+        * target child does not exist, then it will send the request to the
+        * target parent */
        if (fid_is_sane(&op_data->op_fid4)) {
-               struct lmv_tgt_desc *tgt;
+               tgt = lmv_fid2tgt(lmv, &op_data->op_fid4);
+               if (IS_ERR(tgt))
+                       RETURN(PTR_ERR(tgt));
+       } else {
+               tgt = tp_tgt;
+       }
+
+       op_data->op_flags |= MF_MDC_CANCEL_FID4;
+
+       /* cancel UPDATE locks of target parent */
+       rc = lmv_early_cancel(exp, tp_tgt, op_data, tgt->ltd_index, LCK_EX,
+                             MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID2);
+       if (rc != 0)
+               RETURN(rc);
 
-               rc = lmv_early_cancel(exp, NULL, op_data, src_tgt->ltd_idx,
-                                     LCK_EX, MDS_INODELOCK_FULL,
-                                     MF_MDC_CANCEL_FID4);
+       if (fid_is_sane(&op_data->op_fid4)) {
+               /* cancel LOOKUP lock of target on target parent */
+               if (tgt != tp_tgt) {
+                       rc = lmv_early_cancel(exp, tp_tgt, op_data,
+                                             tgt->ltd_index, LCK_EX,
+                                             MDS_INODELOCK_LOOKUP,
+                                             MF_MDC_CANCEL_FID4);
+                       if (rc != 0)
+                               RETURN(rc);
+               }
+       }
+
+       if (fid_is_sane(&op_data->op_fid3)) {
+               src_tgt = lmv_fid2tgt(lmv, &op_data->op_fid3);
+               if (IS_ERR(src_tgt))
+                       RETURN(PTR_ERR(src_tgt));
+
+               /* cancel ELC locks of source */
+               rc = lmv_early_cancel(exp, src_tgt, op_data, tgt->ltd_index,
+                                     LCK_EX, MDS_INODELOCK_ELC,
+                                     MF_MDC_CANCEL_FID3);
                if (rc != 0)
                        RETURN(rc);
+       }
 
-               tgt = lmv_find_target(lmv, &op_data->op_fid4);
-               if (IS_ERR(tgt))
-                       RETURN(PTR_ERR(tgt));
+       op_data->op_name = old;
+       op_data->op_namelen = oldlen;
+retry:
+       sp_tgt = lmv_locate_tgt(lmv, op_data);
+       if (IS_ERR(sp_tgt))
+               RETURN(PTR_ERR(sp_tgt));
+
+       /* cancel UPDATE locks of source parent */
+       rc = lmv_early_cancel(exp, sp_tgt, op_data, tgt->ltd_index, LCK_EX,
+                             MDS_INODELOCK_UPDATE, MF_MDC_CANCEL_FID1);
+       if (rc != 0)
+               RETURN(rc);
 
-               /* Since the target child might be destroyed, and it might
-                * become orphan, and we can only check orphan on the local
-                * MDT right now, so we send rename request to the MDT where
-                * target child is located. If target child does not exist,
-                * then it will send the request to the target parent */
-               target_exp = tgt->ltd_exp;
+       if (fid_is_sane(&op_data->op_fid3)) {
+               /* cancel LOOKUP lock of source on source parent */
+               if (src_tgt != sp_tgt) {
+                       rc = lmv_early_cancel(exp, sp_tgt, op_data,
+                                             tgt->ltd_index, LCK_EX,
+                                             MDS_INODELOCK_LOOKUP,
+                                             MF_MDC_CANCEL_FID3);
+                       if (rc != 0)
+                               RETURN(rc);
+               }
        }
 
-       rc = md_rename(target_exp, op_data, old, oldlen, new, newlen,
-                      request);
+rename:
+       CDEBUG(D_INODE, "RENAME "DFID"/%.*s to "DFID"/%.*s\n",
+               PFID(&op_data->op_fid1), (int)oldlen, old,
+               PFID(&op_data->op_fid2), (int)newlen, new);
+
+       rc = md_rename(tgt->ltd_exp, op_data, old, oldlen, new, newlen,
+                       request);
+       if (rc == -ENOENT && lmv_dir_retry_check_update(op_data)) {
+               ptlrpc_req_finished(*request);
+               *request = NULL;
+               goto retry;
+       }
 
-       if (rc != 0 && rc != -EXDEV)
+       if (rc && rc != -EXDEV)
                RETURN(rc);
 
        body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
@@ -2038,194 +2305,295 @@ retry_rename:
        if (likely(!(body->mbo_valid & OBD_MD_MDS)))
                RETURN(rc);
 
-       CDEBUG(D_INODE, "%s: try rename to another MDT for "DFID"\n",
-              exp->exp_obd->obd_name, PFID(&body->mbo_fid1));
-
        op_data->op_fid4 = body->mbo_fid1;
+
        ptlrpc_req_finished(*request);
        *request = NULL;
-       goto retry_rename;
+
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid4);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
+
+       if (fid_is_sane(&op_data->op_fid4)) {
+               /* cancel LOOKUP lock of target on target parent */
+               if (tgt != tp_tgt) {
+                       rc = lmv_early_cancel(exp, tp_tgt, op_data,
+                                             tgt->ltd_index, LCK_EX,
+                                             MDS_INODELOCK_LOOKUP,
+                                             MF_MDC_CANCEL_FID4);
+                       if (rc != 0)
+                               RETURN(rc);
+               }
+       }
+
+       goto rename;
 }
 
 static int lmv_setattr(struct obd_export *exp, struct md_op_data *op_data,
                       void *ea, size_t ealen, struct ptlrpc_request **request)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt;
-       int                      rc = 0;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc = 0;
+
        ENTRY;
 
-       CDEBUG(D_INODE, "SETATTR for "DFID", valid 0x%x\n",
-              PFID(&op_data->op_fid1), op_data->op_attr.ia_valid);
+       CDEBUG(D_INODE, "SETATTR for "DFID", valid 0x%x/0x%x\n",
+              PFID(&op_data->op_fid1), op_data->op_attr.ia_valid,
+              op_data->op_xvalid);
 
        op_data->op_flags |= MF_MDC_CANCEL_FID1;
-       tgt = lmv_find_target(lmv, &op_data->op_fid1);
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
        rc = md_setattr(tgt->ltd_exp, op_data, ea, ealen, request);
 
-       RETURN(rc);
+       RETURN(rc);
+}
+
+static int lmv_fsync(struct obd_export *exp, const struct lu_fid *fid,
+                    struct ptlrpc_request **request)
+{
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
+       ENTRY;
+
+       tgt = lmv_fid2tgt(lmv, fid);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
+
+       rc = md_fsync(tgt->ltd_exp, fid, request);
+       RETURN(rc);
+}
+
+struct stripe_dirent {
+       struct page             *sd_page;
+       struct lu_dirpage       *sd_dp;
+       struct lu_dirent        *sd_ent;
+       bool                     sd_eof;
+};
+
+struct lmv_dir_ctxt {
+       struct lmv_obd          *ldc_lmv;
+       struct md_op_data       *ldc_op_data;
+       struct md_callback      *ldc_cb_op;
+       __u64                    ldc_hash;
+       int                      ldc_count;
+       struct stripe_dirent     ldc_stripes[0];
+};
+
+static inline void stripe_dirent_unload(struct stripe_dirent *stripe)
+{
+       if (stripe->sd_page) {
+               kunmap(stripe->sd_page);
+               put_page(stripe->sd_page);
+               stripe->sd_page = NULL;
+               stripe->sd_ent = NULL;
+       }
+}
+
+static inline void put_lmv_dir_ctxt(struct lmv_dir_ctxt *ctxt)
+{
+       int i;
+
+       for (i = 0; i < ctxt->ldc_count; i++)
+               stripe_dirent_unload(&ctxt->ldc_stripes[i]);
+}
+
+/* if @ent is dummy, or . .., get next */
+static struct lu_dirent *stripe_dirent_get(struct lmv_dir_ctxt *ctxt,
+                                          struct lu_dirent *ent,
+                                          int stripe_index)
+{
+       for (; ent; ent = lu_dirent_next(ent)) {
+               /* Skip dummy entry */
+               if (le16_to_cpu(ent->lde_namelen) == 0)
+                       continue;
+
+               /* skip . and .. for other stripes */
+               if (stripe_index &&
+                   (strncmp(ent->lde_name, ".",
+                            le16_to_cpu(ent->lde_namelen)) == 0 ||
+                    strncmp(ent->lde_name, "..",
+                            le16_to_cpu(ent->lde_namelen)) == 0))
+                       continue;
+
+               if (le64_to_cpu(ent->lde_hash) >= ctxt->ldc_hash)
+                       break;
+       }
+
+       return ent;
+}
+
+static struct lu_dirent *stripe_dirent_load(struct lmv_dir_ctxt *ctxt,
+                                           struct stripe_dirent *stripe,
+                                           int stripe_index)
+{
+       struct md_op_data *op_data = ctxt->ldc_op_data;
+       struct lmv_oinfo *oinfo;
+       struct lu_fid fid = op_data->op_fid1;
+       struct inode *inode = op_data->op_data;
+       struct lmv_tgt_desc *tgt;
+       struct lu_dirent *ent = stripe->sd_ent;
+       __u64 hash = ctxt->ldc_hash;
+       int rc = 0;
+
+       ENTRY;
+
+       LASSERT(stripe == &ctxt->ldc_stripes[stripe_index]);
+       LASSERT(!ent);
+
+       do {
+               if (stripe->sd_page) {
+                       __u64 end = le64_to_cpu(stripe->sd_dp->ldp_hash_end);
+
+                       /* @hash should be the last dirent hash */
+                       LASSERTF(hash <= end,
+                                "ctxt@%p stripe@%p hash %llx end %llx\n",
+                                ctxt, stripe, hash, end);
+                       /* unload last page */
+                       stripe_dirent_unload(stripe);
+                       /* eof */
+                       if (end == MDS_DIR_END_OFF) {
+                               stripe->sd_eof = true;
+                               break;
+                       }
+                       hash = end;
+               }
+
+               oinfo = &op_data->op_mea1->lsm_md_oinfo[stripe_index];
+               if (!oinfo->lmo_root) {
+                       rc = -ENOENT;
+                       break;
+               }
+
+               tgt = lmv_tgt(ctxt->ldc_lmv, oinfo->lmo_mds);
+               if (!tgt) {
+                       rc = -ENODEV;
+                       break;
+               }
+
+               /* op_data is shared by stripes, reset after use */
+               op_data->op_fid1 = oinfo->lmo_fid;
+               op_data->op_fid2 = oinfo->lmo_fid;
+               op_data->op_data = oinfo->lmo_root;
+
+               rc = md_read_page(tgt->ltd_exp, op_data, ctxt->ldc_cb_op, hash,
+                                 &stripe->sd_page);
+
+               op_data->op_fid1 = fid;
+               op_data->op_fid2 = fid;
+               op_data->op_data = inode;
+
+               if (rc)
+                       break;
+
+               stripe->sd_dp = page_address(stripe->sd_page);
+               ent = stripe_dirent_get(ctxt, lu_dirent_start(stripe->sd_dp),
+                                       stripe_index);
+               /* in case a page filled with ., .. and dummy, read next */
+       } while (!ent);
+
+       stripe->sd_ent = ent;
+       if (rc) {
+               LASSERT(!ent);
+               /* treat error as eof, so dir can be partially accessed */
+               stripe->sd_eof = true;
+               LCONSOLE_WARN("dir "DFID" stripe %d readdir failed: %d, "
+                             "directory is partially accessed!\n",
+                             PFID(&ctxt->ldc_op_data->op_fid1), stripe_index,
+                             rc);
+       }
+
+       RETURN(ent);
 }
 
-static int lmv_fsync(struct obd_export *exp, const struct lu_fid *fid,
-                    struct ptlrpc_request **request)
+static int lmv_file_resync(struct obd_export *exp, struct md_op_data *data)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt;
-       int                      rc;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
        ENTRY;
 
-       tgt = lmv_find_target(lmv, fid);
+       rc = lmv_check_connect(obd);
+       if (rc != 0)
+               RETURN(rc);
+
+       tgt = lmv_fid2tgt(lmv, &data->op_fid1);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
-       rc = md_fsync(tgt->ltd_exp, fid, request);
+       data->op_flags |= MF_MDC_CANCEL_FID1;
+       rc = md_file_resync(tgt->ltd_exp, data);
        RETURN(rc);
 }
 
 /**
- * Get current minimum entry from striped directory
+ * Get dirent with the closest hash for striped directory
  *
  * This function will search the dir entry, whose hash value is the
- * closest(>=) to @hash_offset, from all of sub-stripes, and it is
- * only being called for striped directory.
+ * closest(>=) to hash from all of sub-stripes, and it is only being called
+ * for striped directory.
  *
- * \param[in] exp              export of LMV
- * \param[in] op_data          parameters transferred beween client MD stack
- *                              stripe_information will be included in this
- *                              parameter
- * \param[in] cb_op            ldlm callback being used in enqueue in
- *                              mdc_read_page
- * \param[in] hash_offset      the hash value, which is used to locate
- *                              minum(closet) dir entry
- * \param[in|out] stripe_offset the caller use this to indicate the stripe
- *                              index of last entry, so to avoid hash conflict
- *                              between stripes. It will also be used to
- *                              return the stripe index of current dir entry.
- * \param[in|out] entp         the minum entry and it also is being used
- *                              to input the last dir entry to resolve the
- *                              hash conflict
+ * \param[in] ctxt             dir read context
  *
- * \param[out] ppage           the page which holds the minum entry
- *
- * \retval                      = 0 get the entry successfully
- *                              negative errno (< 0) does not get the entry
+ * \retval                      dirent get the entry successfully
+ *                              NULL does not get the entry, normally it means
+ *                              it reaches the end of the directory, while read
+ *                              stripe dirent error is ignored to allow partial
+ *                              access.
  */
-static int lmv_get_min_striped_entry(struct obd_export *exp,
-                                    struct md_op_data *op_data,
-                                    struct md_callback *cb_op,
-                                    __u64 hash_offset, int *stripe_offset,
-                                    struct lu_dirent **entp,
-                                    struct page **ppage)
-{
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_stripe_md    *lsm = op_data->op_mea1;
-       struct lmv_tgt_desc     *tgt;
-       int                     stripe_count;
-       struct lu_dirent        *min_ent = NULL;
-       struct page             *min_page = NULL;
-       int                     min_idx = 0;
-       int                     i;
-       int                     rc = 0;
-       ENTRY;
-
-       stripe_count = lsm->lsm_md_stripe_count;
-       for (i = 0; i < stripe_count; i++) {
-               struct lu_dirent        *ent = NULL;
-               struct page             *page = NULL;
-               struct lu_dirpage       *dp;
-               __u64                   stripe_hash = hash_offset;
-
-               tgt = lmv_get_target(lmv, lsm->lsm_md_oinfo[i].lmo_mds, NULL);
-               if (IS_ERR(tgt))
-                       GOTO(out, rc = PTR_ERR(tgt));
-
-               /* op_data will be shared by each stripe, so we need
-                * reset these value for each stripe */
-               op_data->op_fid1 = lsm->lsm_md_oinfo[i].lmo_fid;
-               op_data->op_fid2 = lsm->lsm_md_oinfo[i].lmo_fid;
-               op_data->op_data = lsm->lsm_md_oinfo[i].lmo_root;
-next:
-               rc = md_read_page(tgt->ltd_exp, op_data, cb_op, stripe_hash,
-                                 &page);
-               if (rc != 0)
-                       GOTO(out, rc);
-
-               dp = page_address(page);
-               for (ent = lu_dirent_start(dp); ent != NULL;
-                    ent = lu_dirent_next(ent)) {
-                       /* Skip dummy entry */
-                       if (le16_to_cpu(ent->lde_namelen) == 0)
-                               continue;
-
-                       if (le64_to_cpu(ent->lde_hash) < hash_offset)
-                               continue;
-
-                       if (le64_to_cpu(ent->lde_hash) == hash_offset &&
-                           (*entp == ent || i < *stripe_offset))
-                               continue;
-
-                       /* skip . and .. for other stripes */
-                       if (i != 0 &&
-                           (strncmp(ent->lde_name, ".",
-                                    le16_to_cpu(ent->lde_namelen)) == 0 ||
-                            strncmp(ent->lde_name, "..",
-                                    le16_to_cpu(ent->lde_namelen)) == 0))
-                               continue;
-                       break;
-               }
-
-               if (ent == NULL) {
-                       stripe_hash = le64_to_cpu(dp->ldp_hash_end);
+static struct lu_dirent *lmv_dirent_next(struct lmv_dir_ctxt *ctxt)
+{
+       struct stripe_dirent *stripe;
+       struct lu_dirent *ent = NULL;
+       int i;
+       int min = -1;
 
-                       kunmap(page);
-                       page_cache_release(page);
-                       page = NULL;
+       /* TODO: optimize with k-way merge sort */
+       for (i = 0; i < ctxt->ldc_count; i++) {
+               stripe = &ctxt->ldc_stripes[i];
+               if (stripe->sd_eof)
+                       continue;
 
-                       /* reach the end of current stripe, go to next stripe */
-                       if (stripe_hash == MDS_DIR_END_OFF)
+               if (!stripe->sd_ent) {
+                       stripe_dirent_load(ctxt, stripe, i);
+                       if (!stripe->sd_ent) {
+                               LASSERT(stripe->sd_eof);
                                continue;
-                       else
-                               goto next;
+                       }
                }
 
-               if (min_ent != NULL) {
-                       if (le64_to_cpu(min_ent->lde_hash) >
-                           le64_to_cpu(ent->lde_hash)) {
-                               min_ent = ent;
-                               kunmap(min_page);
-                               page_cache_release(min_page);
-                               min_idx = i;
-                               min_page = page;
-                       } else {
-                               kunmap(page);
-                               page_cache_release(page);
-                               page = NULL;
-                       }
-               } else {
-                       min_ent = ent;
-                       min_page = page;
-                       min_idx = i;
+               if (min == -1 ||
+                   le64_to_cpu(ctxt->ldc_stripes[min].sd_ent->lde_hash) >
+                   le64_to_cpu(stripe->sd_ent->lde_hash)) {
+                       min = i;
+                       if (le64_to_cpu(stripe->sd_ent->lde_hash) ==
+                           ctxt->ldc_hash)
+                               break;
                }
        }
 
-out:
-       if (*ppage != NULL) {
-               kunmap(*ppage);
-               page_cache_release(*ppage);
+       if (min != -1) {
+               stripe = &ctxt->ldc_stripes[min];
+               ent = stripe->sd_ent;
+               /* pop found dirent */
+               stripe->sd_ent = stripe_dirent_get(ctxt, lu_dirent_next(ent),
+                                                  min);
        }
-       *stripe_offset = min_idx;
-       *entp = min_ent;
-       *ppage = min_page;
-       RETURN(rc);
+
+       return ent;
 }
 
 /**
- * Build dir entry page from a striped directory
+ * Build dir entry page for striped directory
  *
  * This function gets one entry by @offset from a striped directory. It will
  * read entries from all of stripes, and choose one closest to the required
@@ -2234,12 +2602,11 @@ out:
  * and .. in a directory.
  * 2. op_data will be shared by all of stripes, instead of allocating new
  * one, so need to restore before reusing.
- * 3. release the entry page if that is not being chosen.
  *
  * \param[in] exp      obd export refer to LMV
  * \param[in] op_data  hold those MD parameters of read_entry
  * \param[in] cb_op    ldlm callback being used in enqueue in mdc_read_entry
- * \param[out] ldp     the entry being read
+ * \param[in] offset   starting hash offset
  * \param[out] ppage   the page holding the entry. Note: because the entry
  *                      will be accessed in upper layer, so we need hold the
  *                      page until the usages of entry is finished, see
@@ -2248,143 +2615,139 @@ out:
  * retval              =0 if get entry successfully
  *                      <0 cannot get entry
  */
-static int lmv_read_striped_page(struct obd_export *exp,
+static int lmv_striped_read_page(struct obd_export *exp,
                                 struct md_op_data *op_data,
                                 struct md_callback *cb_op,
                                 __u64 offset, struct page **ppage)
 {
-       struct lu_fid           master_fid = op_data->op_fid1;
-       struct inode            *master_inode = op_data->op_data;
-       __u64                   hash_offset = offset;
-       struct lu_dirpage       *dp;
-       struct page             *min_ent_page = NULL;
-       struct page             *ent_page = NULL;
-       struct lu_dirent        *ent;
-       void                    *area;
-       int                     ent_idx = 0;
-       struct lu_dirent        *min_ent = NULL;
-       struct lu_dirent        *last_ent;
-       size_t                  left_bytes;
-       int                     rc;
+       struct page *page = NULL;
+       struct lu_dirpage *dp;
+       void *start;
+       struct lu_dirent *ent;
+       struct lu_dirent *last_ent;
+       int stripe_count;
+       struct lmv_dir_ctxt *ctxt;
+       struct lu_dirent *next = NULL;
+       __u16 ent_size;
+       size_t left_bytes;
+       int rc = 0;
        ENTRY;
 
        /* Allocate a page and read entries from all of stripes and fill
         * the page by hash order */
-       ent_page = alloc_page(GFP_KERNEL);
-       if (ent_page == NULL)
+       page = alloc_page(GFP_KERNEL);
+       if (!page)
                RETURN(-ENOMEM);
 
        /* Initialize the entry page */
-       dp = kmap(ent_page);
+       dp = kmap(page);
        memset(dp, 0, sizeof(*dp));
        dp->ldp_hash_start = cpu_to_le64(offset);
-       dp->ldp_flags |= LDF_COLLIDE;
 
-       area = dp + 1;
+       start = dp + 1;
        left_bytes = PAGE_SIZE - sizeof(*dp);
-       ent = area;
+       ent = start;
        last_ent = ent;
-       do {
-               __u16   ent_size;
 
-               /* Find the minum entry from all sub-stripes */
-               rc = lmv_get_min_striped_entry(exp, op_data, cb_op, hash_offset,
-                                              &ent_idx, &min_ent,
-                                              &min_ent_page);
-               if (rc != 0)
-                       GOTO(out, rc);
-
-               /* If it can not get minum entry, it means it already reaches
-                * the end of this directory */
-               if (min_ent == NULL) {
-                       last_ent->lde_reclen = 0;
-                       hash_offset = MDS_DIR_END_OFF;
-                       GOTO(out, rc);
+       /* initalize dir read context */
+       stripe_count = op_data->op_mea1->lsm_md_stripe_count;
+       OBD_ALLOC(ctxt, offsetof(typeof(*ctxt), ldc_stripes[stripe_count]));
+       if (!ctxt)
+               GOTO(free_page, rc = -ENOMEM);
+       ctxt->ldc_lmv = &exp->exp_obd->u.lmv;
+       ctxt->ldc_op_data = op_data;
+       ctxt->ldc_cb_op = cb_op;
+       ctxt->ldc_hash = offset;
+       ctxt->ldc_count = stripe_count;
+
+       while (1) {
+               next = lmv_dirent_next(ctxt);
+
+               /* end of directory */
+               if (!next) {
+                       ctxt->ldc_hash = MDS_DIR_END_OFF;
+                       break;
                }
+               ctxt->ldc_hash = le64_to_cpu(next->lde_hash);
 
-               ent_size = le16_to_cpu(min_ent->lde_reclen);
+               ent_size = le16_to_cpu(next->lde_reclen);
 
-               /* the last entry lde_reclen is 0, but it might not
-                * the end of this entry of this temporay entry */
-               if (ent_size == 0)
+               /* the last entry lde_reclen is 0, but it might not be the last
+                * one of this temporay dir page */
+               if (!ent_size)
                        ent_size = lu_dirent_calc_size(
-                                       le16_to_cpu(min_ent->lde_namelen),
-                                       le32_to_cpu(min_ent->lde_attrs));
-               if (ent_size > left_bytes) {
-                       last_ent->lde_reclen = cpu_to_le16(0);
-                       hash_offset = le64_to_cpu(min_ent->lde_hash);
-                       GOTO(out, rc);
-               }
+                                       le16_to_cpu(next->lde_namelen),
+                                       le32_to_cpu(next->lde_attrs));
+               /* page full */
+               if (ent_size > left_bytes)
+                       break;
 
-               memcpy(ent, min_ent, ent_size);
+               memcpy(ent, next, ent_size);
 
                /* Replace . with master FID and Replace .. with the parent FID
                 * of master object */
                if (strncmp(ent->lde_name, ".",
                            le16_to_cpu(ent->lde_namelen)) == 0 &&
                    le16_to_cpu(ent->lde_namelen) == 1)
-                       fid_cpu_to_le(&ent->lde_fid, &master_fid);
+                       fid_cpu_to_le(&ent->lde_fid, &op_data->op_fid1);
                else if (strncmp(ent->lde_name, "..",
                                   le16_to_cpu(ent->lde_namelen)) == 0 &&
                           le16_to_cpu(ent->lde_namelen) == 2)
                        fid_cpu_to_le(&ent->lde_fid, &op_data->op_fid3);
 
+               CDEBUG(D_INODE, "entry %.*s hash %#llx\n",
+                      le16_to_cpu(ent->lde_namelen), ent->lde_name,
+                      le64_to_cpu(ent->lde_hash));
+
                left_bytes -= ent_size;
                ent->lde_reclen = cpu_to_le16(ent_size);
                last_ent = ent;
                ent = (void *)ent + ent_size;
-               hash_offset = le64_to_cpu(min_ent->lde_hash);
-               if (hash_offset == MDS_DIR_END_OFF) {
-                       last_ent->lde_reclen = 0;
-                       break;
-               }
-       } while (1);
-out:
-       if (min_ent_page != NULL) {
-               kunmap(min_ent_page);
-               page_cache_release(min_ent_page);
-       }
+       };
 
-       if (unlikely(rc != 0)) {
-               __free_page(ent_page);
-               ent_page = NULL;
-       } else {
-               if (ent == area)
-                       dp->ldp_flags |= LDF_EMPTY;
-               dp->ldp_flags = cpu_to_le32(dp->ldp_flags);
-               dp->ldp_hash_end = cpu_to_le64(hash_offset);
-       }
+       last_ent->lde_reclen = 0;
 
-       /* We do not want to allocate md_op_data during each
-        * dir entry reading, so op_data will be shared by every stripe,
-        * then we need to restore it back to original value before
-        * return to the upper layer */
-       op_data->op_fid1 = master_fid;
-       op_data->op_fid2 = master_fid;
-       op_data->op_data = master_inode;
+       if (ent == start)
+               dp->ldp_flags |= LDF_EMPTY;
+       else if (ctxt->ldc_hash == le64_to_cpu(last_ent->lde_hash))
+               dp->ldp_flags |= LDF_COLLIDE;
+       dp->ldp_flags = cpu_to_le32(dp->ldp_flags);
+       dp->ldp_hash_end = cpu_to_le64(ctxt->ldc_hash);
 
-       *ppage = ent_page;
+       put_lmv_dir_ctxt(ctxt);
+       OBD_FREE(ctxt, offsetof(typeof(*ctxt), ldc_stripes[stripe_count]));
 
-       RETURN(rc);
+       *ppage = page;
+
+       RETURN(0);
+
+free_page:
+       kunmap(page);
+       __free_page(page);
+
+       return rc;
 }
 
 int lmv_read_page(struct obd_export *exp, struct md_op_data *op_data,
                  struct md_callback *cb_op, __u64 offset,
                  struct page **ppage)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_stripe_md    *lsm = op_data->op_mea1;
-       struct lmv_tgt_desc     *tgt;
-       int                     rc;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
+
        ENTRY;
 
-       if (unlikely(lsm != NULL)) {
-               rc = lmv_read_striped_page(exp, op_data, cb_op, offset, ppage);
+       if (unlikely(lmv_dir_foreign(op_data->op_mea1)))
+               RETURN(-ENODATA);
+
+       if (unlikely(lmv_dir_striped(op_data->op_mea1))) {
+               rc = lmv_striped_read_page(exp, op_data, cb_op, offset, ppage);
                RETURN(rc);
        }
 
-       tgt = lmv_find_target(lmv, &op_data->op_fid1);
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
@@ -2418,68 +2781,34 @@ int lmv_read_page(struct obd_export *exp, struct md_op_data *op_data,
  *                      negative errno if failed.
  */
 static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
-                      struct ptlrpc_request **request)
+                     struct ptlrpc_request **request)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt = NULL;
-       struct lmv_tgt_desc     *parent_tgt = NULL;
-       struct mdt_body         *body;
-       int                     rc;
-       int                     stripe_index = 0;
-       struct lmv_stripe_md    *lsm = op_data->op_mea1;
-       ENTRY;
-
-retry_unlink:
-       /* For striped dir, we need to locate the parent as well */
-       if (lsm != NULL) {
-               struct lmv_tgt_desc *tmp;
-
-               LASSERT(op_data->op_name != NULL &&
-                       op_data->op_namelen != 0);
-
-               tmp = lmv_locate_target_for_name(lmv, lsm,
-                                                op_data->op_name,
-                                                op_data->op_namelen,
-                                                &op_data->op_fid1,
-                                                &op_data->op_mds);
-
-               /* return -EBADFD means unknown hash type, might
-                * need try all sub-stripe here */
-               if (IS_ERR(tmp) && PTR_ERR(tmp) != -EBADFD)
-                       RETURN(PTR_ERR(tmp));
-
-               /* Note: both migrating dir and unknown hash dir need to
-                * try all of sub-stripes, so we need start search the
-                * name from stripe 0, but migrating dir is already handled
-                * inside lmv_locate_target_for_name(), so we only check
-                * unknown hash type directory here */
-               if (!lmv_is_known_hash_type(lsm->lsm_md_hash_type)) {
-                       struct lmv_oinfo *oinfo;
-
-                       oinfo = &lsm->lsm_md_oinfo[stripe_index];
-
-                       op_data->op_fid1 = oinfo->lmo_fid;
-                       op_data->op_mds = oinfo->lmo_mds;
-               }
-       }
-
-try_next_stripe:
-       /* Send unlink requests to the MDT where the child is located */
-       if (likely(!fid_is_zero(&op_data->op_fid2)))
-               tgt = lmv_find_target(lmv, &op_data->op_fid2);
-       else if (lsm != NULL)
-               tgt = lmv_get_target(lmv, op_data->op_mds, NULL);
-       else
-               tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       struct lmv_tgt_desc *parent_tgt;
+       struct mdt_body *body;
+       int rc;
 
-       if (IS_ERR(tgt))
-               RETURN(PTR_ERR(tgt));
+       ENTRY;
 
        op_data->op_fsuid = from_kuid(&init_user_ns, current_fsuid());
        op_data->op_fsgid = from_kgid(&init_user_ns, current_fsgid());
        op_data->op_cap = cfs_curproc_cap_pack();
 
+retry:
+       parent_tgt = lmv_locate_tgt(lmv, op_data);
+       if (IS_ERR(parent_tgt))
+               RETURN(PTR_ERR(parent_tgt));
+
+       if (likely(!fid_is_zero(&op_data->op_fid2))) {
+               tgt = lmv_fid2tgt(lmv, &op_data->op_fid2);
+               if (IS_ERR(tgt))
+                       RETURN(PTR_ERR(tgt));
+       } else {
+               tgt = parent_tgt;
+       }
+
        /*
         * If child's fid is given, cancel unused locks for it if it is from
         * another export than parent.
@@ -2489,50 +2818,30 @@ try_next_stripe:
         */
        op_data->op_flags |= MF_MDC_CANCEL_FID1 | MF_MDC_CANCEL_FID3;
 
-       /*
-        * Cancel FULL locks on child (fid3).
-        */
-       parent_tgt = lmv_find_target(lmv, &op_data->op_fid1);
-       if (IS_ERR(parent_tgt))
-               RETURN(PTR_ERR(parent_tgt));
-
-       if (parent_tgt != tgt) {
-               rc = lmv_early_cancel(exp, parent_tgt, op_data, tgt->ltd_idx,
+       if (parent_tgt != tgt)
+               rc = lmv_early_cancel(exp, parent_tgt, op_data, tgt->ltd_index,
                                      LCK_EX, MDS_INODELOCK_LOOKUP,
                                      MF_MDC_CANCEL_FID3);
-       }
 
-       rc = lmv_early_cancel(exp, NULL, op_data, tgt->ltd_idx, LCK_EX,
-                             MDS_INODELOCK_FULL, MF_MDC_CANCEL_FID3);
-       if (rc != 0)
+       rc = lmv_early_cancel(exp, NULL, op_data, tgt->ltd_index, LCK_EX,
+                             MDS_INODELOCK_ELC, MF_MDC_CANCEL_FID3);
+       if (rc)
                RETURN(rc);
 
        CDEBUG(D_INODE, "unlink with fid="DFID"/"DFID" -> mds #%u\n",
-              PFID(&op_data->op_fid1), PFID(&op_data->op_fid2), tgt->ltd_idx);
+              PFID(&op_data->op_fid1), PFID(&op_data->op_fid2),
+              tgt->ltd_index);
 
        rc = md_unlink(tgt->ltd_exp, op_data, request);
-       if (rc != 0 && rc != -EREMOTE && rc != -ENOENT)
-               RETURN(rc);
-
-       /* Try next stripe if it is needed. */
-       if (rc == -ENOENT && lsm != NULL && lmv_need_try_all_stripes(lsm)) {
-               struct lmv_oinfo *oinfo;
-
-               stripe_index++;
-               if (stripe_index >= lsm->lsm_md_stripe_count)
-                       RETURN(rc);
-
-               oinfo = &lsm->lsm_md_oinfo[stripe_index];
-
-               op_data->op_fid1 = oinfo->lmo_fid;
-               op_data->op_mds = oinfo->lmo_mds;
-
+       if (rc == -ENOENT && lmv_dir_retry_check_update(op_data)) {
                ptlrpc_req_finished(*request);
                *request = NULL;
-
-               goto try_next_stripe;
+               goto retry;
        }
 
+       if (rc != -EREMOTE)
+               RETURN(rc);
+
        body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
        if (body == NULL)
                RETURN(-EPROTO);
@@ -2541,39 +2850,23 @@ try_next_stripe:
        if (likely(!(body->mbo_valid & OBD_MD_MDS)))
                RETURN(rc);
 
-       CDEBUG(D_INODE, "%s: try unlink to another MDT for "DFID"\n",
-              exp->exp_obd->obd_name, PFID(&body->mbo_fid1));
-
-       /* This is a remote object, try remote MDT, Note: it may
-        * try more than 1 time here, Considering following case
-        * /mnt/lustre is root on MDT0, remote1 is on MDT1
-        * 1. Initially A does not know where remote1 is, it send
-        *    unlink RPC to MDT0, MDT0 return -EREMOTE, it will
-        *    resend unlink RPC to MDT1 (retry 1st time).
-        *
-        * 2. During the unlink RPC in flight,
-        *    client B mv /mnt/lustre/remote1 /mnt/lustre/remote2
-        *    and create new remote1, but on MDT0
-        *
-        * 3. MDT1 get unlink RPC(from A), then do remote lock on
-        *    /mnt/lustre, then lookup get fid of remote1, and find
-        *    it is remote dir again, and replay -EREMOTE again.
-        *
-        * 4. Then A will resend unlink RPC to MDT0. (retry 2nd times).
-        *
-        * In theory, it might try unlimited time here, but it should
-        * be very rare case.  */
+       /* This is a remote object, try remote MDT. */
        op_data->op_fid2 = body->mbo_fid1;
        ptlrpc_req_finished(*request);
        *request = NULL;
 
-       goto retry_unlink;
+       tgt = lmv_fid2tgt(lmv, &op_data->op_fid2);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
+
+       goto retry;
 }
 
 static int lmv_precleanup(struct obd_device *obd)
 {
        ENTRY;
-       fld_client_proc_fini(&obd->u.lmv.lmv_fld);
+       libcfs_kkuc_group_rem(&obd->obd_uuid, 0, KUC_GRP_HSM);
+       fld_client_debugfs_fini(&obd->u.lmv.lmv_fld);
        lprocfs_obd_cleanup(obd);
        lprocfs_free_md_stats(obd);
        RETURN(0);
@@ -2598,31 +2891,24 @@ static int lmv_precleanup(struct obd_device *obd)
 static int lmv_get_info(const struct lu_env *env, struct obd_export *exp,
                        __u32 keylen, void *key, __u32 *vallen, void *val)
 {
-        struct obd_device       *obd;
-        struct lmv_obd          *lmv;
-        int                      rc = 0;
-        ENTRY;
-
-        obd = class_exp2obd(exp);
-        if (obd == NULL) {
-               CDEBUG(D_IOCTL, "Invalid client cookie %#llx\n",
-                       exp->exp_handle.h_cookie);
-                RETURN(-EINVAL);
-        }
+       struct obd_device *obd;
+       struct lmv_obd *lmv;
+       struct lu_tgt_desc *tgt;
+       int rc = 0;
 
-        lmv = &obd->u.lmv;
-        if (keylen >= strlen("remote_flag") && !strcmp(key, "remote_flag")) {
-                int i;
+       ENTRY;
 
-                LASSERT(*vallen == sizeof(__u32));
-               for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-                       struct lmv_tgt_desc *tgt = lmv->tgts[i];
-                       /*
-                        * All tgts should be connected when this gets called.
-                        */
-                       if (tgt == NULL || tgt->ltd_exp == NULL)
-                               continue;
+       obd = class_exp2obd(exp);
+       if (obd == NULL) {
+               CDEBUG(D_IOCTL, "Invalid client cookie %#llx\n",
+                      exp->exp_handle.h_cookie);
+               RETURN(-EINVAL);
+       }
 
+       lmv = &obd->u.lmv;
+       if (keylen >= strlen("remote_flag") && !strcmp(key, "remote_flag")) {
+               LASSERT(*vallen == sizeof(__u32));
+               lmv_foreach_connected_tgt(lmv, tgt) {
                        if (!obd_get_info(env, tgt->ltd_exp, keylen, key,
                                          vallen, val))
                                RETURN(0);
@@ -2635,18 +2921,112 @@ static int lmv_get_info(const struct lu_env *env, struct obd_export *exp,
                 * Forwarding this request to first MDS, it should know LOV
                 * desc.
                 */
-               rc = obd_get_info(env, lmv->tgts[0]->ltd_exp, keylen, key,
-                                 vallen, val);
+               tgt = lmv_tgt(lmv, 0);
+               if (!tgt)
+                       RETURN(-ENODEV);
+
+               rc = obd_get_info(env, tgt->ltd_exp, keylen, key, vallen, val);
                if (!rc && KEY_IS(KEY_CONN_DATA))
                        exp->exp_connect_data = *(struct obd_connect_data *)val;
-                RETURN(rc);
-        } else if (KEY_IS(KEY_TGT_COUNT)) {
-                *((int *)val) = lmv->desc.ld_tgt_count;
-                RETURN(0);
-        }
+               RETURN(rc);
+       } else if (KEY_IS(KEY_TGT_COUNT)) {
+               *((int *)val) = lmv->lmv_mdt_descs.ltd_tgts_size;
+               RETURN(0);
+       }
+
+       CDEBUG(D_IOCTL, "Invalid key\n");
+       RETURN(-EINVAL);
+}
+
+static int lmv_rmfid(struct obd_export *exp, struct fid_array *fa,
+                    int *__rcs, struct ptlrpc_request_set *_set)
+{
+       struct obd_device *obddev = class_exp2obd(exp);
+       struct ptlrpc_request_set *set = _set;
+       struct lmv_obd *lmv = &obddev->u.lmv;
+       int tgt_count = lmv->lmv_mdt_count;
+       struct lu_tgt_desc *tgt;
+       struct fid_array *fat, **fas = NULL;
+       int i, rc, **rcs = NULL;
+
+       if (!set) {
+               set = ptlrpc_prep_set();
+               if (!set)
+                       RETURN(-ENOMEM);
+       }
+
+       /* split FIDs by targets */
+       OBD_ALLOC(fas, sizeof(fas) * tgt_count);
+       if (fas == NULL)
+               GOTO(out, rc = -ENOMEM);
+       OBD_ALLOC(rcs, sizeof(int *) * tgt_count);
+       if (rcs == NULL)
+               GOTO(out_fas, rc = -ENOMEM);
+
+       for (i = 0; i < fa->fa_nr; i++) {
+               unsigned int idx;
+
+               rc = lmv_fld_lookup(lmv, &fa->fa_fids[i], &idx);
+               if (rc) {
+                       CDEBUG(D_OTHER, "can't lookup "DFID": rc = %d\n",
+                              PFID(&fa->fa_fids[i]), rc);
+                       continue;
+               }
+               LASSERT(idx < tgt_count);
+               if (!fas[idx])
+                       OBD_ALLOC(fas[idx], offsetof(struct fid_array,
+                                 fa_fids[fa->fa_nr]));
+               if (!fas[idx])
+                       GOTO(out, rc = -ENOMEM);
+               if (!rcs[idx])
+                       OBD_ALLOC(rcs[idx], sizeof(int) * fa->fa_nr);
+               if (!rcs[idx])
+                       GOTO(out, rc = -ENOMEM);
+
+               fat = fas[idx];
+               fat->fa_fids[fat->fa_nr++] = fa->fa_fids[i];
+       }
+
+       lmv_foreach_connected_tgt(lmv, tgt) {
+               fat = fas[tgt->ltd_index];
+               if (!fat || fat->fa_nr == 0)
+                       continue;
+               rc = md_rmfid(tgt->ltd_exp, fat, rcs[tgt->ltd_index], set);
+       }
+
+       rc = ptlrpc_set_wait(NULL, set);
+       if (rc == 0) {
+               int j = 0;
+               for (i = 0; i < tgt_count; i++) {
+                       fat = fas[i];
+                       if (!fat || fat->fa_nr == 0)
+                               continue;
+                       /* copy FIDs back */
+                       memcpy(fa->fa_fids + j, fat->fa_fids,
+                              fat->fa_nr * sizeof(struct lu_fid));
+                       /* copy rcs back */
+                       memcpy(__rcs + j, rcs[i], fat->fa_nr * sizeof(**rcs));
+                       j += fat->fa_nr;
+               }
+       }
+       if (set != _set)
+               ptlrpc_set_destroy(set);
+
+out:
+       for (i = 0; i < tgt_count; i++) {
+               if (fas && fas[i])
+                       OBD_FREE(fas[i], offsetof(struct fid_array,
+                                               fa_fids[fa->fa_nr]));
+               if (rcs && rcs[i])
+                       OBD_FREE(rcs[i], sizeof(int) * fa->fa_nr);
+       }
+       if (rcs)
+               OBD_FREE(rcs, sizeof(int *) * tgt_count);
+out_fas:
+       if (fas)
+               OBD_FREE(fas, sizeof(fas) * tgt_count);
 
-        CDEBUG(D_IOCTL, "Invalid key\n");
-        RETURN(-EINVAL);
+       RETURN(rc);
 }
 
 /**
@@ -2685,14 +3065,9 @@ int lmv_set_info_async(const struct lu_env *env, struct obd_export *exp,
 
        if (KEY_IS(KEY_READ_ONLY) || KEY_IS(KEY_FLUSH_CTX) ||
            KEY_IS(KEY_DEFAULT_EASIZE)) {
-               int i, err = 0;
-
-               for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-                       tgt = lmv->tgts[i];
-
-                       if (tgt == NULL || tgt->ltd_exp == NULL)
-                               continue;
+               int err = 0;
 
+               lmv_foreach_connected_tgt(lmv, tgt) {
                        err = obd_set_info_async(env, tgt->ltd_exp,
                                                 keylen, key, vallen, val, set);
                        if (err && rc == 0)
@@ -2723,13 +3098,15 @@ static int lmv_unpack_md_v1(struct obd_export *exp, struct lmv_stripe_md *lsm,
        else
                lsm->lsm_md_hash_type = le32_to_cpu(lmm1->lmv_hash_type);
        lsm->lsm_md_layout_version = le32_to_cpu(lmm1->lmv_layout_version);
+       lsm->lsm_md_migrate_offset = le32_to_cpu(lmm1->lmv_migrate_offset);
+       lsm->lsm_md_migrate_hash = le32_to_cpu(lmm1->lmv_migrate_hash);
        cplen = strlcpy(lsm->lsm_md_pool_name, lmm1->lmv_pool_name,
                        sizeof(lsm->lsm_md_pool_name));
 
        if (cplen >= sizeof(lsm->lsm_md_pool_name))
                RETURN(-E2BIG);
 
-       CDEBUG(D_INFO, "unpack lsm count %d, master %d hash_type %d"
+       CDEBUG(D_INFO, "unpack lsm count %d, master %d hash_type %#x "
               "layout_version %d\n", lsm->lsm_md_stripe_count,
               lsm->lsm_md_master_mdt_index, lsm->lsm_md_hash_type,
               lsm->lsm_md_layout_version);
@@ -2738,10 +3115,22 @@ static int lmv_unpack_md_v1(struct obd_export *exp, struct lmv_stripe_md *lsm,
        for (i = 0; i < stripe_count; i++) {
                fid_le_to_cpu(&lsm->lsm_md_oinfo[i].lmo_fid,
                              &lmm1->lmv_stripe_fids[i]);
+               /*
+                * set default value -1, so lmv_locate_tgt() knows this stripe
+                * target is not initialized.
+                */
+               lsm->lsm_md_oinfo[i].lmo_mds = LMV_OFFSET_DEFAULT;
+               if (!fid_is_sane(&lsm->lsm_md_oinfo[i].lmo_fid))
+                       continue;
+
                rc = lmv_fld_lookup(lmv, &lsm->lsm_md_oinfo[i].lmo_fid,
                                    &lsm->lsm_md_oinfo[i].lmo_mds);
-               if (rc != 0)
+               if (rc == -ENOENT)
+                       continue;
+
+               if (rc)
                        RETURN(rc);
+
                CDEBUG(D_INFO, "unpack fid #%d "DFID"\n", i,
                       PFID(&lsm->lsm_md_oinfo[i].lmo_fid));
        }
@@ -2749,6 +3138,18 @@ static int lmv_unpack_md_v1(struct obd_export *exp, struct lmv_stripe_md *lsm,
        RETURN(rc);
 }
 
+static inline int lmv_unpack_user_md(struct obd_export *exp,
+                                    struct lmv_stripe_md *lsm,
+                                    const struct lmv_user_md *lmu)
+{
+       lsm->lsm_md_magic = le32_to_cpu(lmu->lum_magic);
+       lsm->lsm_md_stripe_count = le32_to_cpu(lmu->lum_stripe_count);
+       lsm->lsm_md_master_mdt_index = le32_to_cpu(lmu->lum_stripe_offset);
+       lsm->lsm_md_hash_type = le32_to_cpu(lmu->lum_hash_type);
+
+       return 0;
+}
+
 static int lmv_unpackmd(struct obd_export *exp, struct lmv_stripe_md **lsmp,
                        const union lmv_mds_md *lmm, size_t lmm_size)
 {
@@ -2764,20 +3165,50 @@ static int lmv_unpackmd(struct obd_export *exp, struct lmv_stripe_md **lsmp,
        /* Free memmd */
        if (lsm != NULL && lmm == NULL) {
                int i;
-               for (i = 0; i < lsm->lsm_md_stripe_count; i++) {
-                       /* For migrating inode, the master stripe and master
-                        * object will be the same, so do not need iput, see
-                        * ll_update_lsm_md */
-                       if (!(lsm->lsm_md_hash_type & LMV_HASH_FLAG_MIGRATION &&
-                             i == 0) && lsm->lsm_md_oinfo[i].lmo_root != NULL)
-                               iput(lsm->lsm_md_oinfo[i].lmo_root);
+               struct lmv_foreign_md *lfm = (struct lmv_foreign_md *)lsm;
+
+               if (lfm->lfm_magic == LMV_MAGIC_FOREIGN) {
+                       size_t lfm_size;
+
+                       lfm_size = lfm->lfm_length + offsetof(typeof(*lfm),
+                                                             lfm_value[0]);
+                       OBD_FREE_LARGE(lfm, lfm_size);
+                       RETURN(0);
+               }
+
+               if (lmv_dir_striped(lsm)) {
+                       for (i = 0; i < lsm->lsm_md_stripe_count; i++) {
+                               if (lsm->lsm_md_oinfo[i].lmo_root)
+                                       iput(lsm->lsm_md_oinfo[i].lmo_root);
+                       }
+                       lsm_size = lmv_stripe_md_size(lsm->lsm_md_stripe_count);
+               } else {
+                       lsm_size = lmv_stripe_md_size(0);
                }
-               lsm_size = lmv_stripe_md_size(lsm->lsm_md_stripe_count);
                OBD_FREE(lsm, lsm_size);
                *lsmp = NULL;
                RETURN(0);
        }
 
+       /* foreign lmv case */
+       if (le32_to_cpu(lmm->lmv_magic) == LMV_MAGIC_FOREIGN) {
+               struct lmv_foreign_md *lfm = (struct lmv_foreign_md *)lsm;
+
+               if (lfm == NULL) {
+                       OBD_ALLOC_LARGE(lfm, lmm_size);
+                       if (lfm == NULL)
+                               RETURN(-ENOMEM);
+                       *lsmp = (struct lmv_stripe_md *)lfm;
+               }
+               lfm->lfm_magic = le32_to_cpu(lmm->lmv_foreign_md.lfm_magic);
+               lfm->lfm_length = le32_to_cpu(lmm->lmv_foreign_md.lfm_length);
+               lfm->lfm_type = le32_to_cpu(lmm->lmv_foreign_md.lfm_type);
+               lfm->lfm_flags = le32_to_cpu(lmm->lmv_foreign_md.lfm_flags);
+               memcpy(&lfm->lfm_value, &lmm->lmv_foreign_md.lfm_value,
+                      lfm->lfm_length);
+               RETURN(lmm_size);
+       }
+
        if (le32_to_cpu(lmm->lmv_magic) == LMV_MAGIC_STRIPE)
                RETURN(-EPERM);
 
@@ -2799,7 +3230,6 @@ static int lmv_unpackmd(struct obd_export *exp, struct lmv_stripe_md **lsmp,
                 */
                lsm_size = lmv_stripe_md_size(0);
 
-       lsm_size = lmv_stripe_md_size(lmv_mds_md_stripe_count_get(lmm));
        if (lsm == NULL) {
                OBD_ALLOC(lsm, lsm_size);
                if (lsm == NULL)
@@ -2812,6 +3242,9 @@ static int lmv_unpackmd(struct obd_export *exp, struct lmv_stripe_md **lsmp,
        case LMV_MAGIC_V1:
                rc = lmv_unpack_md_v1(exp, lsm, &lmm->lmv_md_v1);
                break;
+       case LMV_USER_MAGIC:
+               rc = lmv_unpack_user_md(exp, lsm, &lmm->lmv_user_md);
+               break;
        default:
                CERROR("%s: unrecognized magic %x\n", exp->exp_obd->obd_name,
                       le32_to_cpu(lmm->lmv_magic));
@@ -2839,17 +3272,16 @@ static int lmv_cancel_unused(struct obd_export *exp, const struct lu_fid *fid,
                             void *opaque)
 {
        struct lmv_obd *lmv = &exp->exp_obd->u.lmv;
+       struct lu_tgt_desc *tgt;
+       int err;
        int rc = 0;
-       __u32 i;
+
        ENTRY;
 
        LASSERT(fid != NULL);
 
-       for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
-               struct lmv_tgt_desc *tgt = lmv->tgts[i];
-               int err;
-
-               if (tgt == NULL || tgt->ltd_exp == NULL || !tgt->ltd_active)
+       lmv_foreach_connected_tgt(lmv, tgt) {
+               if (!tgt->ltd_active)
                        continue;
 
                err = md_cancel_unused(tgt->ltd_exp, fid, policy, mode, flags,
@@ -2864,9 +3296,10 @@ static int lmv_set_lock_data(struct obd_export *exp,
                             const struct lustre_handle *lockh,
                             void *data, __u64 *bits)
 {
-       struct lmv_obd          *lmv = &exp->exp_obd->u.lmv;
-       struct lmv_tgt_desc     *tgt = lmv->tgts[0];
-       int                      rc;
+       struct lmv_obd *lmv = &exp->exp_obd->u.lmv;
+       struct lmv_tgt_desc *tgt = lmv_tgt(lmv, 0);
+       int rc;
+
        ENTRY;
 
        if (tgt == NULL || tgt->ltd_exp == NULL)
@@ -2880,37 +3313,38 @@ enum ldlm_mode lmv_lock_match(struct obd_export *exp, __u64 flags,
                              union ldlm_policy_data *policy,
                              enum ldlm_mode mode, struct lustre_handle *lockh)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       enum ldlm_mode          rc;
-       int                     tgt;
-       int                     i;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       enum ldlm_mode rc;
+       struct lu_tgt_desc *tgt;
+       int i;
+       int index;
+
        ENTRY;
 
        CDEBUG(D_INODE, "Lock match for "DFID"\n", PFID(fid));
 
-        /*
+       /*
         * With DNE every object can have two locks in different namespaces:
         * lookup lock in space of MDT storing direntry and update/open lock in
         * space of MDT storing inode.  Try the MDT that the FID maps to first,
         * since this can be easily found, and only try others if that fails.
         */
-       for (i = 0, tgt = lmv_find_target_index(lmv, fid);
-            i < lmv->desc.ld_tgt_count;
-            i++, tgt = (tgt + 1) % lmv->desc.ld_tgt_count) {
-               if (tgt < 0) {
+       for (i = 0, index = lmv_fid2tgt_index(lmv, fid);
+            i < lmv->lmv_mdt_descs.ltd_tgts_size;
+            i++, index = (index + 1) % lmv->lmv_mdt_descs.ltd_tgts_size) {
+               if (index < 0) {
                        CDEBUG(D_HA, "%s: "DFID" is inaccessible: rc = %d\n",
-                              obd->obd_name, PFID(fid), tgt);
-                       tgt = 0;
+                              obd->obd_name, PFID(fid), index);
+                       index = 0;
                }
 
-               if (lmv->tgts[tgt] == NULL ||
-                   lmv->tgts[tgt]->ltd_exp == NULL ||
-                   lmv->tgts[tgt]->ltd_active == 0)
+               tgt = lmv_tgt(lmv, index);
+               if (!tgt || !tgt->ltd_exp || !tgt->ltd_active)
                        continue;
 
-               rc = md_lock_match(lmv->tgts[tgt]->ltd_exp, flags, fid,
-                                  type, policy, mode, lockh);
+               rc = md_lock_match(tgt->ltd_exp, flags, fid, type, policy, mode,
+                                  lockh);
                if (rc)
                        RETURN(rc);
        }
@@ -2922,41 +3356,47 @@ int lmv_get_lustre_md(struct obd_export *exp, struct ptlrpc_request *req,
                      struct obd_export *dt_exp, struct obd_export *md_exp,
                      struct lustre_md *md)
 {
-       struct lmv_obd          *lmv = &exp->exp_obd->u.lmv;
-       struct lmv_tgt_desc     *tgt = lmv->tgts[0];
+       struct lmv_obd *lmv = &exp->exp_obd->u.lmv;
+       struct lmv_tgt_desc *tgt = lmv_tgt(lmv, 0);
 
-       if (tgt == NULL || tgt->ltd_exp == NULL)
-               RETURN(-EINVAL);
+       if (!tgt || !tgt->ltd_exp)
+               return -EINVAL;
 
-       return md_get_lustre_md(lmv->tgts[0]->ltd_exp, req, dt_exp, md_exp, md);
+       return md_get_lustre_md(tgt->ltd_exp, req, dt_exp, md_exp, md);
 }
 
 int lmv_free_lustre_md(struct obd_export *exp, struct lustre_md *md)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt = lmv->tgts[0];
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt = lmv_tgt(lmv, 0);
+
        ENTRY;
 
+       if (md->default_lmv) {
+               lmv_free_memmd(md->default_lmv);
+               md->default_lmv = NULL;
+       }
        if (md->lmv != NULL) {
                lmv_free_memmd(md->lmv);
                md->lmv = NULL;
        }
-       if (tgt == NULL || tgt->ltd_exp == NULL)
+       if (!tgt || !tgt->ltd_exp)
                RETURN(-EINVAL);
-       RETURN(md_free_lustre_md(lmv->tgts[0]->ltd_exp, md));
+       RETURN(md_free_lustre_md(tgt->ltd_exp, md));
 }
 
 int lmv_set_open_replay_data(struct obd_export *exp,
                             struct obd_client_handle *och,
                             struct lookup_intent *it)
 {
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *tgt;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+
        ENTRY;
 
-       tgt = lmv_find_target(lmv, &och->och_fid);
+       tgt = lmv_fid2tgt(lmv, &och->och_fid);
        if (IS_ERR(tgt))
                RETURN(PTR_ERR(tgt));
 
@@ -2964,70 +3404,72 @@ int lmv_set_open_replay_data(struct obd_export *exp,
 }
 
 int lmv_clear_open_replay_data(struct obd_export *exp,
-                               struct obd_client_handle *och)
+                              struct obd_client_handle *och)
 {
-        struct obd_device       *obd = exp->exp_obd;
-        struct lmv_obd          *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc     *tgt;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
 
-        tgt = lmv_find_target(lmv, &och->och_fid);
-        if (IS_ERR(tgt))
-                RETURN(PTR_ERR(tgt));
+       ENTRY;
+
+       tgt = lmv_fid2tgt(lmv, &och->och_fid);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
 
-        RETURN(md_clear_open_replay_data(tgt->ltd_exp, och));
+       RETURN(md_clear_open_replay_data(tgt->ltd_exp, och));
 }
 
 int lmv_intent_getattr_async(struct obd_export *exp,
                             struct md_enqueue_info *minfo)
 {
-       struct md_op_data       *op_data = &minfo->mi_data;
-       struct obd_device       *obd = exp->exp_obd;
-       struct lmv_obd          *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc     *ptgt = NULL;
-       struct lmv_tgt_desc     *ctgt = NULL;
-       int                      rc;
+       struct md_op_data *op_data = &minfo->mi_data;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *ptgt;
+       struct lmv_tgt_desc *ctgt;
+       int rc;
+
        ENTRY;
 
        if (!fid_is_sane(&op_data->op_fid2))
                RETURN(-EINVAL);
 
-       ptgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+       ptgt = lmv_locate_tgt(lmv, op_data);
        if (IS_ERR(ptgt))
                RETURN(PTR_ERR(ptgt));
 
-       ctgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid2);
+       ctgt = lmv_fid2tgt(lmv, &op_data->op_fid1);
        if (IS_ERR(ctgt))
                RETURN(PTR_ERR(ctgt));
 
        /*
-        * if child is on remote MDT, we need 2 async RPCs to fetch both LOOKUP
-        * lock on parent, and UPDATE lock on child MDT, which makes all
-        * complicated. Considering remote dir is rare case, and not supporting
-        * it in statahead won't cause any issue, drop its support for now.
+        * remote object needs two RPCs to lookup and getattr, considering the
+        * complexity don't support statahead for now.
         */
-       if (ptgt != ctgt)
-               RETURN(-ENOTSUPP);
+       if (ctgt != ptgt)
+               RETURN(-EREMOTE);
 
        rc = md_intent_getattr_async(ptgt->ltd_exp, minfo);
+
        RETURN(rc);
 }
 
 int lmv_revalidate_lock(struct obd_export *exp, struct lookup_intent *it,
-                        struct lu_fid *fid, __u64 *bits)
+                       struct lu_fid *fid, __u64 *bits)
 {
-        struct obd_device       *obd = exp->exp_obd;
-        struct lmv_obd          *lmv = &obd->u.lmv;
-        struct lmv_tgt_desc     *tgt;
-        int                      rc;
-        ENTRY;
+       struct obd_device *obd = exp->exp_obd;
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt;
+       int rc;
 
-        tgt = lmv_find_target(lmv, fid);
-        if (IS_ERR(tgt))
-                RETURN(PTR_ERR(tgt));
+       ENTRY;
+
+       tgt = lmv_fid2tgt(lmv, fid);
+       if (IS_ERR(tgt))
+               RETURN(PTR_ERR(tgt));
 
-        rc = md_revalidate_lock(tgt->ltd_exp, it, fid, bits);
-        RETURN(rc);
+       rc = md_revalidate_lock(tgt->ltd_exp, it, fid, bits);
+       RETURN(rc);
 }
 
 int lmv_get_fid_from_lsm(struct obd_export *exp,
@@ -3036,8 +3478,9 @@ int lmv_get_fid_from_lsm(struct obd_export *exp,
 {
        const struct lmv_oinfo *oinfo;
 
-       LASSERT(lsm != NULL);
-       oinfo = lsm_name_to_stripe_info(lsm, name, namelen);
+       LASSERT(lmv_dir_striped(lsm));
+
+       oinfo = lsm_name_to_stripe_info(lsm, name, namelen, false);
        if (IS_ERR(oinfo))
                return PTR_ERR(oinfo);
 
@@ -3054,49 +3497,46 @@ int lmv_get_fid_from_lsm(struct obd_export *exp,
 int lmv_quotactl(struct obd_device *unused, struct obd_export *exp,
                 struct obd_quotactl *oqctl)
 {
-       struct obd_device   *obd = class_exp2obd(exp);
-       struct lmv_obd      *lmv = &obd->u.lmv;
-       struct lmv_tgt_desc *tgt = lmv->tgts[0];
-       int                  rc = 0;
-       __u32                i;
-       __u64                curspace, curinodes;
+       struct obd_device *obd = class_exp2obd(exp);
+       struct lmv_obd *lmv = &obd->u.lmv;
+       struct lmv_tgt_desc *tgt = lmv_tgt(lmv, 0);
+       __u64 curspace, curinodes;
+       int rc = 0;
+
        ENTRY;
 
-       if (tgt == NULL ||
-           tgt->ltd_exp == NULL ||
-           !tgt->ltd_active ||
-           lmv->desc.ld_tgt_count == 0) {
+       if (!tgt || !tgt->ltd_exp || !tgt->ltd_active) {
                CERROR("master lmv inactive\n");
                RETURN(-EIO);
        }
 
-        if (oqctl->qc_cmd != Q_GETOQUOTA) {
-                rc = obd_quotactl(tgt->ltd_exp, oqctl);
-                RETURN(rc);
-        }
+       if (oqctl->qc_cmd != Q_GETOQUOTA) {
+               rc = obd_quotactl(tgt->ltd_exp, oqctl);
+               RETURN(rc);
+       }
 
-        curspace = curinodes = 0;
-        for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+       curspace = curinodes = 0;
+       lmv_foreach_connected_tgt(lmv, tgt) {
                int err;
-               tgt = lmv->tgts[i];
 
-               if (tgt == NULL || tgt->ltd_exp == NULL || !tgt->ltd_active)
+               if (!tgt->ltd_active)
                        continue;
 
-                err = obd_quotactl(tgt->ltd_exp, oqctl);
-                if (err) {
-                        CERROR("getquota on mdt %d failed. %d\n", i, err);
-                        if (!rc)
-                                rc = err;
-                } else {
-                        curspace += oqctl->qc_dqblk.dqb_curspace;
-                        curinodes += oqctl->qc_dqblk.dqb_curinodes;
-                }
-        }
-        oqctl->qc_dqblk.dqb_curspace = curspace;
-        oqctl->qc_dqblk.dqb_curinodes = curinodes;
+               err = obd_quotactl(tgt->ltd_exp, oqctl);
+               if (err) {
+                       CERROR("getquota on mdt %d failed. %d\n",
+                              tgt->ltd_index, err);
+                       if (!rc)
+                               rc = err;
+               } else {
+                       curspace += oqctl->qc_dqblk.dqb_curspace;
+                       curinodes += oqctl->qc_dqblk.dqb_curinodes;
+               }
+       }
+       oqctl->qc_dqblk.dqb_curspace = curspace;
+       oqctl->qc_dqblk.dqb_curinodes = curinodes;
 
-        RETURN(rc);
+       RETURN(rc);
 }
 
 static int lmv_merge_attr(struct obd_export *exp,
@@ -3107,6 +3547,9 @@ static int lmv_merge_attr(struct obd_export *exp,
        int rc;
        int i;
 
+       if (!lmv_dir_striped(lsm))
+               return 0;
+
        rc = lmv_revalidate_slaves(exp, lsm, cb_blocking, 0);
        if (rc < 0)
                return rc;
@@ -3114,12 +3557,15 @@ static int lmv_merge_attr(struct obd_export *exp,
        for (i = 0; i < lsm->lsm_md_stripe_count; i++) {
                struct inode *inode = lsm->lsm_md_oinfo[i].lmo_root;
 
-               CDEBUG(D_INFO, ""DFID" size %llu, blocks %llu nlink %u,"
-                      " atime %lu ctime %lu, mtime %lu.\n",
+               if (!inode)
+                       continue;
+
+               CDEBUG(D_INFO,
+                      "" DFID " size %llu, blocks %llu nlink %u, atime %lld ctime %lld, mtime %lld.\n",
                       PFID(&lsm->lsm_md_oinfo[i].lmo_fid),
                       i_size_read(inode), (unsigned long long)inode->i_blocks,
-                      inode->i_nlink, LTIME_S(inode->i_atime),
-                      LTIME_S(inode->i_ctime), LTIME_S(inode->i_mtime));
+                      inode->i_nlink, (s64)inode->i_atime.tv_sec,
+                      (s64)inode->i_ctime.tv_sec, (s64)inode->i_mtime.tv_sec);
 
                /* for slave stripe, it needs to subtract nlink for . and .. */
                if (i != 0)
@@ -3130,14 +3576,14 @@ static int lmv_merge_attr(struct obd_export *exp,
                attr->cat_size += i_size_read(inode);
                attr->cat_blocks += inode->i_blocks;
 
-               if (attr->cat_atime < LTIME_S(inode->i_atime))
-                       attr->cat_atime = LTIME_S(inode->i_atime);
+               if (attr->cat_atime < inode->i_atime.tv_sec)
+                       attr->cat_atime = inode->i_atime.tv_sec;
 
-               if (attr->cat_ctime < LTIME_S(inode->i_ctime))
-                       attr->cat_ctime = LTIME_S(inode->i_ctime);
+               if (attr->cat_ctime < inode->i_ctime.tv_sec)
+                       attr->cat_ctime = inode->i_ctime.tv_sec;
 
-               if (attr->cat_mtime < LTIME_S(inode->i_mtime))
-                       attr->cat_mtime = LTIME_S(inode->i_mtime);
+               if (attr->cat_mtime < inode->i_mtime.tv_sec)
+                       attr->cat_mtime = inode->i_mtime.tv_sec;
        }
        return 0;
 }
@@ -3155,6 +3601,7 @@ struct obd_ops lmv_obd_ops = {
         .o_set_info_async       = lmv_set_info_async,
         .o_notify               = lmv_notify,
         .o_get_uuid             = lmv_get_uuid,
+       .o_fid_alloc            = lmv_fid_alloc,
         .o_iocontrol            = lmv_iocontrol,
         .o_quotactl             = lmv_quotactl
 };
@@ -3174,6 +3621,7 @@ struct md_ops lmv_md_ops = {
         .m_setattr              = lmv_setattr,
         .m_setxattr             = lmv_setxattr,
        .m_fsync                = lmv_fsync,
+       .m_file_resync          = lmv_file_resync,
        .m_read_page            = lmv_read_page,
         .m_unlink               = lmv_unlink,
         .m_init_ea_size         = lmv_init_ea_size,
@@ -3189,6 +3637,7 @@ struct md_ops lmv_md_ops = {
        .m_revalidate_lock      = lmv_revalidate_lock,
        .m_get_fid_from_lsm     = lmv_get_fid_from_lsm,
        .m_unpackmd             = lmv_unpackmd,
+       .m_rmfid                = lmv_rmfid,
 };
 
 static int __init lmv_init(void)