diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_user.h b/drivers/staging/lustre/lustre/include/lustre/lustre_user.h
index 9e38ed38681f..52cd5855c865 100644
--- a/drivers/staging/lustre/lustre/include/lustre/lustre_user.h
+++ b/drivers/staging/lustre/lustre/include/lustre/lustre_user.h
@@ -383,6 +383,7 @@ struct lmv_user_mds_data {
 };
 
 enum lmv_hash_type {
+	LMV_HASH_TYPE_UNKNOWN	= 0,	/* 0 is reserved for testing purpose */
 	LMV_HASH_TYPE_ALL_CHARS = 1,
 	LMV_HASH_TYPE_FNV_1A_64 = 2,
 };
diff --git a/drivers/staging/lustre/lustre/include/obd_support.h b/drivers/staging/lustre/lustre/include/obd_support.h
index a11fff1e55c8..f747bca94aa1 100644
--- a/drivers/staging/lustre/lustre/include/obd_support.h
+++ b/drivers/staging/lustre/lustre/include/obd_support.h
@@ -483,6 +483,9 @@ extern char obd_jobid_var[];
 #define OBD_FAIL_UPDATE_OBJ_NET			0x1700
 #define OBD_FAIL_UPDATE_OBJ_NET_REP		0x1701
 
+/* LMV */
+#define OBD_FAIL_UNKNOWN_LMV_STRIPE		0x1901
+
 /* Assign references to moved code to reduce code changes */
 #define OBD_FAIL_PRECHECK(id)		   CFS_FAIL_PRECHECK(id)
 #define OBD_FAIL_CHECK(id)		      CFS_FAIL_CHECK(id)
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_intent.c b/drivers/staging/lustre/lustre/lmv/lmv_intent.c
index cde1d7b6bfc2..055944514fcf 100644
--- a/drivers/staging/lustre/lustre/lmv/lmv_intent.c
+++ b/drivers/staging/lustre/lustre/lmv/lmv_intent.c
@@ -402,10 +402,28 @@ static int lmv_intent_lookup(struct obd_export *exp,
 	struct mdt_body	*body;
 	int		     rc = 0;
 
+	/*
+	 * If it returns ERR_PTR(-EBADFD) then it is an unknown hash type
+	 * it will try all stripes to locate the object
+	 */
 	tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
-	if (IS_ERR(tgt))
+	if (IS_ERR(tgt) && (PTR_ERR(tgt) != -EBADFD))
 		return PTR_ERR(tgt);
 
+	/*
+	 * Both migrating dir and unknown hash dir need to try
+	 * all of sub-stripes
+	 */
+	if (lsm && !lmv_is_known_hash_type(lsm)) {
+		struct lmv_oinfo *oinfo = &lsm->lsm_md_oinfo[0];
+
+		op_data->op_fid1 = oinfo->lmo_fid;
+		op_data->op_mds = oinfo->lmo_mds;
+		tgt = lmv_get_target(lmv, oinfo->lmo_mds, NULL);
+		if (IS_ERR(tgt))
+			return PTR_ERR(tgt);
+	}
+
 	if (!fid_is_sane(&op_data->op_fid2))
 		fid_zero(&op_data->op_fid2);
 
@@ -435,27 +453,39 @@ static int lmv_intent_lookup(struct obd_export *exp,
 		}
 		return rc;
 	} else if (it_disposition(it, DISP_LOOKUP_NEG) && lsm &&
-		   lsm->lsm_md_magic & LMV_HASH_FLAG_MIGRATION) {
+		   lmv_need_try_all_stripes(lsm)) {
 		/*
-		 * For migrating directory, if it can not find the child in
-		 * the source directory(master stripe), try the targeting
-		 * directory(stripe 1)
+		 * For migrating and unknown hash type directory, it will
+		 * try to target the entry on other stripes
 		 */
-		tgt = lmv_find_target(lmv, &lsm->lsm_md_oinfo[1].lmo_fid);
-		if (IS_ERR(tgt))
-			return PTR_ERR(tgt);
+		int stripe_index;
 
-		ptlrpc_req_finished(*reqp);
-		it->it_request = NULL;
-		*reqp = NULL;
+		for (stripe_index = 1;
+		     stripe_index < lsm->lsm_md_stripe_count &&
+		     it_disposition(it, DISP_LOOKUP_NEG); stripe_index++) {
+			struct lmv_oinfo *oinfo;
 
-		CDEBUG(D_INODE, "For migrating dir, try target dir "DFID"\n",
-		       PFID(&lsm->lsm_md_oinfo[1].lmo_fid));
+			/* release the previous request */
+			ptlrpc_req_finished(*reqp);
+			it->it_request = NULL;
+			*reqp = NULL;
 
-		op_data->op_fid1 = lsm->lsm_md_oinfo[1].lmo_fid;
-		it->it_disposition &= ~DISP_ENQ_COMPLETE;
-		rc = md_intent_lock(tgt->ltd_exp, op_data, lmm, lmmsize, it,
-				    flags, reqp, cb_blocking, extra_lock_flags);
+			oinfo = &lsm->lsm_md_oinfo[stripe_index];
+			tgt = lmv_find_target(lmv, &oinfo->lmo_fid);
+			if (IS_ERR(tgt))
+				return PTR_ERR(tgt);
+
+			CDEBUG(D_INODE, "Try other stripes " DFID"\n",
+			       PFID(&oinfo->lmo_fid));
+
+			op_data->op_fid1 = oinfo->lmo_fid;
+			it->it_disposition &= ~DISP_ENQ_COMPLETE;
+			rc = md_intent_lock(tgt->ltd_exp, op_data, lmm,
+					    lmmsize, it, flags, reqp,
+					    cb_blocking, extra_lock_flags);
+			if (rc)
+				return rc;
+		}
 	}
 
 	/*
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_internal.h b/drivers/staging/lustre/lustre/lmv/lmv_internal.h
index faf6a7ba8637..ea528ae1aa2b 100644
--- a/drivers/staging/lustre/lustre/lmv/lmv_internal.h
+++ b/drivers/staging/lustre/lustre/lmv/lmv_internal.h
@@ -147,6 +147,18 @@ lsm_name_to_stripe_info(const struct lmv_stripe_md *lsm, const char *name,
 	return &lsm->lsm_md_oinfo[stripe_index];
 }
 
+static inline bool lmv_is_known_hash_type(const struct lmv_stripe_md *lsm)
+{
+	return lsm->lsm_md_hash_type == LMV_HASH_TYPE_FNV_1A_64 ||
+	       lsm->lsm_md_hash_type == LMV_HASH_TYPE_ALL_CHARS;
+}
+
+static inline bool lmv_need_try_all_stripes(const struct lmv_stripe_md *lsm)
+{
+	return !lmv_is_known_hash_type(lsm) ||
+	       lsm->lsm_md_hash_type & LMV_HASH_FLAG_MIGRATION;
+}
+
 struct lmv_tgt_desc
 *lmv_locate_mds(struct lmv_obd *lmv, struct md_op_data *op_data,
 		struct lu_fid *fid);
diff --git a/drivers/staging/lustre/lustre/lmv/lmv_obd.c b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
index 27a6be122a77..e9f4e9a0a939 100644
--- a/drivers/staging/lustre/lustre/lmv/lmv_obd.c
+++ b/drivers/staging/lustre/lustre/lmv/lmv_obd.c
@@ -102,8 +102,8 @@ int lmv_name_to_stripe_index(__u32 lmv_hash_type, unsigned int stripe_count,
 		idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 		break;
 	default:
-		CERROR("Unknown hash type 0x%x\n", hash_type);
-		return -EINVAL;
+		idx = -EBADFD;
+		break;
 	}
 
 	CDEBUG(D_INFO, "name %.*s hash_type %d idx %d\n", namelen, name,
@@ -1697,6 +1697,23 @@ lmv_locate_target_for_name(struct lmv_obd *lmv, struct lmv_stripe_md *lsm,
 	return tgt;
 }
 
+/**
+ * Locate mds by fid or name
+ *
+ * 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 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)
@@ -2351,45 +2368,94 @@ static int lmv_readpage(struct obd_export *exp, struct md_op_data *op_data,
 	return rc;
 }
 
+/**
+ * Unlink a file/directory
+ *
+ * Unlink a file or directory under the parent dir. The unlink request
+ * usually will be sent to the MDT where the child is located, but if
+ * the client does not have the child FID then request will be sent to the
+ * MDT where the parent is located.
+ *
+ * If the parent is a striped directory then it also needs to locate which
+ * stripe the name of the child is located, and replace the parent FID
+ * (@op->op_fid1) with the stripe FID. Note: if the stripe is unknown,
+ * it will walk through all of sub-stripes until the child is being
+ * unlinked finally.
+ *
+ * \param[in] exp	export refer to LMV
+ * \param[in] op_data	different parameters transferred beween client
+ *			MD stacks, name, namelen, FIDs etc.
+ *			op_fid1 is the parent FID, op_fid2 is the child
+ *			FID.
+ * \param[out] request point to the request of unlink.
+ *
+ * retval		0 if succeed
+ *			negative errno if failed.
+ */
 static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
 		      struct ptlrpc_request **request)
 {
-	struct obd_device       *obd = exp->exp_obd;
+	struct lmv_stripe_md *lsm = op_data->op_mea1;
+	struct obd_device    *obd = exp->exp_obd;
 	struct lmv_obd	  *lmv = &obd->u.lmv;
 	struct lmv_tgt_desc *parent_tgt = NULL;
 	struct lmv_tgt_desc     *tgt = NULL;
 	struct mdt_body		*body;
+	int stripe_index = 0;
 	int		     rc;
 
 	rc = lmv_check_connect(obd);
 	if (rc)
 		return rc;
-retry:
-	/* 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);
-		if (IS_ERR(tgt))
-			return PTR_ERR(tgt);
+retry_unlink:
+	/* For striped dir, we need to locate the parent as well */
+	if (lsm) {
+		struct lmv_tgt_desc *tmp;
 
-		/* For striped dir, we need to locate the parent as well */
-		if (op_data->op_mea1) {
-			struct lmv_tgt_desc *tmp;
+		LASSERT(op_data->op_name && op_data->op_namelen);
 
-			LASSERT(op_data->op_name && op_data->op_namelen);
-			tmp = lmv_locate_target_for_name(lmv, op_data->op_mea1,
-							 op_data->op_name,
-							 op_data->op_namelen,
-							 &op_data->op_fid1,
-							 &op_data->op_mds);
-			if (IS_ERR(tmp))
-				return PTR_ERR(tmp);
+		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)) {
+			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;
 		}
-	} else {
-		tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
-		if (IS_ERR(tgt))
-			return PTR_ERR(tgt);
 	}
 
+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)
+		tgt = lmv_get_target(lmv, op_data->op_mds, NULL);
+	else
+		tgt = lmv_locate_mds(lmv, op_data, &op_data->op_fid1);
+
+	if (IS_ERR(tgt))
+		return PTR_ERR(tgt);
+
 	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();
@@ -2425,9 +2491,28 @@ static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
 	       PFID(&op_data->op_fid1), PFID(&op_data->op_fid2), tgt->ltd_idx);
 
 	rc = md_unlink(tgt->ltd_exp, op_data, request);
-	if (rc != 0 && rc != -EREMOTE)
+	if (rc != 0 && rc != -EREMOTE  && rc != -ENOENT)
 		return rc;
 
+	/* Try next stripe if it is needed. */
+	if (rc == -ENOENT && lsm && 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;
+
+		ptlrpc_req_finished(*request);
+		*request = NULL;
+
+		goto try_next_stripe;
+	}
+
 	body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
 	if (!body)
 		return -EPROTO;
@@ -2463,7 +2548,7 @@ static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
 	ptlrpc_req_finished(*request);
 	*request = NULL;
 
-	goto retry;
+	goto retry_unlink;
 }
 
 static int lmv_precleanup(struct obd_device *obd, enum obd_cleanup_stage stage)
@@ -2683,7 +2768,10 @@ static int lmv_unpack_md_v1(struct obd_export *exp, struct lmv_stripe_md *lsm,
 	lsm->lsm_md_magic = le32_to_cpu(lmm1->lmv_magic);
 	lsm->lsm_md_stripe_count = le32_to_cpu(lmm1->lmv_stripe_count);
 	lsm->lsm_md_master_mdt_index = le32_to_cpu(lmm1->lmv_master_mdt_index);
-	lsm->lsm_md_hash_type = le32_to_cpu(lmm1->lmv_hash_type);
+	if (OBD_FAIL_CHECK(OBD_FAIL_UNKNOWN_LMV_STRIPE))
+		lsm->lsm_md_hash_type = LMV_HASH_TYPE_UNKNOWN;
+	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);
 	fid_le_to_cpu(&lsm->lsm_md_master_fid, &lmm1->lmv_master_fid);
 	cplen = strlcpy(lsm->lsm_md_pool_name, lmm1->lmv_pool_name,