diff --git a/fs/lustre/include/lu_object.h b/fs/lustre/include/lu_object.h
index c34605c..0f3e3be 100644
--- a/fs/lustre/include/lu_object.h
+++ b/fs/lustre/include/lu_object.h
@@ -1303,5 +1303,93 @@ struct lu_kmem_descr {
 extern u32 lu_context_tags_default;
 extern u32 lu_session_tags_default;
 
+/* Generic subset of OSTs */
+struct ost_pool {
+	u32		   *op_array;	/* array of index of
+					 * lov_obd->lov_tgts
+					 */
+	unsigned int	    op_count;	/* number of OSTs in the array */
+	unsigned int	    op_size;	/* allocated size of lp_array */
+	struct rw_semaphore op_rw_sem;	/* to protect ost_pool use */
+};
+
+/* round-robin QoS data for LOD/LMV */
+struct lu_qos_rr {
+	spinlock_t		 lqr_alloc;	/* protect allocation index */
+	u32			 lqr_start_idx;	/* start index of new inode */
+	u32			 lqr_offset_idx;/* aliasing for start_idx */
+	int			 lqr_start_count;/* reseed counter */
+	struct ost_pool		 lqr_pool;	/* round-robin optimized list */
+	unsigned long		 lqr_dirty:1;	/* recalc round-robin list */
+};
+
+/* QoS data per MDS/OSS */
+struct lu_svr_qos {
+	struct obd_uuid		 lsq_uuid;	/* ptlrpc's c_remote_uuid */
+	struct list_head	 lsq_svr_list;	/* link to lq_svr_list */
+	u64			 lsq_bavail;	/* total bytes avail on svr */
+	u64			 lsq_iavail;	/* tital inode avail on svr */
+	u64			 lsq_penalty;	/* current penalty */
+	u64			 lsq_penalty_per_obj; /* penalty decrease
+						       * every obj
+						       */
+	time64_t		 lsq_used;	/* last used time, seconds */
+	u32			 lsq_tgt_count;	/* number of tgts on this svr */
+	u32			 lsq_id;	/* unique svr id */
+};
+
+/* QoS data per MDT/OST */
+struct lu_tgt_qos {
+	struct lu_svr_qos	*ltq_svr;	/* svr info */
+	u64			 ltq_penalty;	/* current penalty */
+	u64			 ltq_penalty_per_obj; /* penalty decrease
+						       * every obj
+						       */
+	u64			 ltq_weight;	/* net weighting */
+	time64_t		 ltq_used;	/* last used time, seconds */
+	bool			 ltq_usable:1;	/* usable for striping */
+};
+
+/* target descriptor */
+struct lu_tgt_desc {
+	union {
+		struct dt_device	*ltd_tgt;
+		struct obd_device	*ltd_obd;
+	};
+	struct obd_export		*ltd_exp;
+	struct obd_uuid			ltd_uuid;
+	u32				ltd_index;
+	u32				ltd_gen;
+	struct list_head		ltd_kill;
+	struct ptlrpc_thread		*ltd_recovery_thread;
+	struct mutex			ltd_fid_mutex;
+	struct lu_tgt_qos		ltd_qos; /* qos info per target */
+	struct obd_statfs		ltd_statfs;
+	time64_t			ltd_statfs_age;
+	unsigned long	ltd_active:1,	/* is this target up for requests */
+			ltd_activate:1,	/* should target be activated */
+			ltd_reap:1,	/* should this target be deleted */
+			ltd_got_update_log:1, /* Already got update log */
+			ltd_connecting:1;  /* target is connecting */
+};
+
+/* QoS data for LOD/LMV */
+struct lu_qos {
+	struct list_head	 lq_svr_list;	/* lu_svr_qos list */
+	struct rw_semaphore	 lq_rw_sem;
+	u32			 lq_active_svr_count;
+	unsigned int		 lq_prio_free;   /* priority for free space */
+	unsigned int		 lq_threshold_rr;/* priority for rr */
+	struct lu_qos_rr	 lq_rr;          /* round robin qos data */
+	unsigned long		 lq_dirty:1,     /* recalc qos data */
+				 lq_same_space:1,/* the servers all have approx.
+						  * the same space avail
+						  */
+				 lq_reset:1;     /* zero current penalties */
+};
+
+int lqos_add_tgt(struct lu_qos *qos, struct lu_tgt_desc *ltd);
+int lqos_del_tgt(struct lu_qos *qos, struct lu_tgt_desc *ltd);
+
 /** @} lu */
 #endif /* __LUSTRE_LU_OBJECT_H */
diff --git a/fs/lustre/include/obd.h b/fs/lustre/include/obd.h
index e815584..2f878d6 100644
--- a/fs/lustre/include/obd.h
+++ b/fs/lustre/include/obd.h
@@ -87,7 +87,7 @@ struct obd_info {
 	/* OBD_STATFS_* flags */
 	u64			oi_flags;
 	struct obd_device      *oi_obd;
-	struct lmv_tgt_desc    *oi_tgt;
+	struct lu_tgt_desc     *oi_tgt;
 	/* lsm data specific for every OSC. */
 	struct lov_stripe_md   *oi_md;
 	/* statfs data specific for every OSC, if needed at all. */
@@ -377,28 +377,10 @@ struct echo_client_obd {
 	u64			ec_unique;
 };
 
-/* Generic subset of OSTs */
-struct ost_pool {
-	u32			*op_array;  /* array of index of lov_obd->lov_tgts */
-	unsigned int		 op_count;  /* number of OSTs in the array */
-	unsigned int		 op_size;   /* allocated size of lp_array */
-	struct rw_semaphore	 op_rw_sem; /* to protect ost_pool use */
-};
-
 /* allow statfs data caching for 1 second */
 #define OBD_STATFS_CACHE_SECONDS 1
 
-struct lov_tgt_desc {
-	struct list_head	ltd_kill;
-	struct obd_uuid		ltd_uuid;
-	struct obd_device      *ltd_obd;
-	struct obd_export      *ltd_exp;
-	u32			ltd_gen;
-	u32			ltd_index;   /* index in lov_obd->tgts */
-	unsigned long		ltd_active:1,/* is this target up for requests */
-				ltd_activate:1,/* should  target be activated */
-				ltd_reap:1;  /* should this target be deleted */
-};
+#define lov_tgt_desc lu_tgt_desc
 
 struct lov_md_tgt_desc {
 	struct obd_device *lmtd_mdc;
@@ -431,16 +413,7 @@ struct lov_obd {
 	struct lov_md_tgt_desc	*lov_mdc_tgts;
 };
 
-struct lmv_tgt_desc {
-	struct obd_uuid		ltd_uuid;
-	struct obd_device	*ltd_obd;
-	struct obd_export      *ltd_exp;
-	u32			ltd_idx;
-	struct mutex		ltd_fid_mutex;
-	struct obd_statfs	ltd_statfs;
-	time64_t		ltd_statfs_age;
-	unsigned long		ltd_active:1; /* target up for requests */
-};
+#define lmv_tgt_desc lu_tgt_desc
 
 struct lmv_obd {
 	struct lu_client_fld	lmv_fld;
@@ -458,6 +431,9 @@ struct lmv_obd {
 	struct obd_connect_data	conn_data;
 	struct kobject		*lmv_tgts_kobj;
 	void			*lmv_cache;
+
+	struct lu_qos		lmv_qos;
+	u32			lmv_qos_rr_index;
 };
 
 struct niobuf_local {
diff --git a/fs/lustre/lmv/Makefile b/fs/lustre/lmv/Makefile
index ad470bf..6f9a19c 100644
--- a/fs/lustre/lmv/Makefile
+++ b/fs/lustre/lmv/Makefile
@@ -1,4 +1,4 @@
 ccflags-y += -I$(srctree)/$(src)/../include
 
 obj-$(CONFIG_LUSTRE_FS) += lmv.o
-lmv-y := lmv_obd.o lmv_intent.o lmv_fld.o lproc_lmv.o
+lmv-y := lmv_obd.o lmv_intent.o lmv_fld.o lproc_lmv.o lmv_qos.o
diff --git a/fs/lustre/lmv/lmv_intent.c b/fs/lustre/lmv/lmv_intent.c
index 6017375..3efd977 100644
--- a/fs/lustre/lmv/lmv_intent.c
+++ b/fs/lustre/lmv/lmv_intent.c
@@ -108,7 +108,7 @@ static int lmv_intent_remote(struct obd_export *exp, struct lookup_intent *it,
 
 	op_data->op_bias = MDS_CROSS_REF;
 	CDEBUG(D_INODE, "REMOTE_INTENT with fid=" DFID " -> mds #%u\n",
-	       PFID(&body->mbo_fid1), tgt->ltd_idx);
+	       PFID(&body->mbo_fid1), tgt->ltd_index);
 
 	/* ask for security context upon intent */
 	if (it->it_op & (IT_LOOKUP | IT_GETATTR | IT_OPEN) &&
@@ -206,7 +206,7 @@ int lmv_revalidate_slaves(struct obd_export *exp,
 		}
 
 		CDEBUG(D_INODE, "Revalidate slave " DFID " -> mds #%u\n",
-		       PFID(&fid), tgt->ltd_idx);
+		       PFID(&fid), tgt->ltd_index);
 
 		if (req) {
 			ptlrpc_req_finished(req);
@@ -353,7 +353,7 @@ static int lmv_intent_open(struct obd_export *exp, struct md_op_data *op_data,
 		if (IS_ERR(tgt))
 			return PTR_ERR(tgt);
 
-		op_data->op_mds = tgt->ltd_idx;
+		op_data->op_mds = tgt->ltd_index;
 	} else {
 		LASSERT(fid_is_sane(&op_data->op_fid1));
 		LASSERT(fid_is_zero(&op_data->op_fid2));
@@ -380,7 +380,7 @@ static int lmv_intent_open(struct obd_export *exp, struct md_op_data *op_data,
 	CDEBUG(D_INODE,
 	       "OPEN_INTENT with fid1=" DFID ", fid2=" DFID ", name='%s' -> mds #%u\n",
 	       PFID(&op_data->op_fid1),
-	       PFID(&op_data->op_fid2), op_data->op_name, tgt->ltd_idx);
+	       PFID(&op_data->op_fid2), op_data->op_name, tgt->ltd_index);
 
 	rc = md_intent_lock(tgt->ltd_exp, op_data, it, reqp, cb_blocking,
 			    extra_lock_flags);
@@ -465,7 +465,7 @@ static int lmv_intent_lookup(struct obd_export *exp,
 	       "LOOKUP_INTENT with fid1=" DFID ", fid2=" DFID ", name='%s' -> mds #%u\n",
 	       PFID(&op_data->op_fid1), PFID(&op_data->op_fid2),
 	       op_data->op_name ? op_data->op_name : "<NULL>",
-	       tgt->ltd_idx);
+	       tgt->ltd_index);
 
 	op_data->op_bias &= ~MDS_CROSS_REF;
 
diff --git a/fs/lustre/lmv/lmv_internal.h b/fs/lustre/lmv/lmv_internal.h
index 9974ec5..c673656 100644
--- a/fs/lustre/lmv/lmv_internal.h
+++ b/fs/lustre/lmv/lmv_internal.h
@@ -60,6 +60,8 @@ int lmv_revalidate_slaves(struct obd_export *exp,
 
 int lmv_getattr_name(struct obd_export *exp, struct md_op_data *op_data,
 		     struct ptlrpc_request **preq);
+void lmv_activate_target(struct lmv_obd *lmv, struct lmv_tgt_desc *tgt,
+			 int activate);
 
 int lmv_statfs_check_update(struct obd_device *obd, struct lmv_tgt_desc *tgt);
 
@@ -77,7 +79,7 @@ static inline struct obd_device *lmv2obd_dev(struct lmv_obd *lmv)
 		if (!lmv->tgts[i])
 			continue;
 
-		if (lmv->tgts[i]->ltd_idx == mdt_idx) {
+		if (lmv->tgts[i]->ltd_index == mdt_idx) {
 			if (index)
 				*index = i;
 			return lmv->tgts[i];
@@ -192,6 +194,10 @@ static inline bool lmv_dir_retry_check_update(struct md_op_data *op_data)
 struct lmv_tgt_desc *lmv_locate_tgt(struct lmv_obd *lmv,
 				    struct md_op_data *op_data);
 
+/* lmv_qos.c */
+struct lu_tgt_desc *lmv_locate_tgt_qos(struct lmv_obd *lmv, u32 *mdt);
+struct lu_tgt_desc *lmv_locate_tgt_rr(struct lmv_obd *lmv, u32 *mdt);
+
 /* lproc_lmv.c */
 int lmv_tunables_init(struct obd_device *obd);
 
diff --git a/fs/lustre/lmv/lmv_obd.c b/fs/lustre/lmv/lmv_obd.c
index 02dfd35..20ae322 100644
--- a/fs/lustre/lmv/lmv_obd.c
+++ b/fs/lustre/lmv/lmv_obd.c
@@ -57,9 +57,8 @@
 
 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;
@@ -315,7 +314,7 @@ static int lmv_connect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
 
 	target.ft_srv = NULL;
 	target.ft_exp = mdc_exp;
-	target.ft_idx = tgt->ltd_idx;
+	target.ft_idx = tgt->ltd_index;
 
 	fld_client_add_target(&lmv->lmv_fld, &target);
 
@@ -345,6 +344,12 @@ static int lmv_connect_mdc(struct obd_device *obd, struct lmv_tgt_desc *tgt)
 
 	md_init_ea_size(tgt->ltd_exp, lmv->max_easize, lmv->max_def_easize);
 
+	rc = lqos_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));
@@ -364,6 +369,8 @@ static void lmv_del_target(struct lmv_obd *lmv, int index)
 	if (!lmv->tgts[index])
 		return;
 
+	lqos_del_tgt(&lmv->lmv_qos, lmv->tgts[index]);
+
 	kfree(lmv->tgts[index]);
 	lmv->tgts[index] = NULL;
 }
@@ -435,7 +442,7 @@ static int lmv_add_target(struct obd_device *obd, struct obd_uuid *uuidp,
 	}
 
 	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;
@@ -1099,7 +1106,7 @@ static int lmv_iocontrol(unsigned int cmd, struct obd_export *exp,
 			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);
@@ -1253,6 +1260,8 @@ static int lmv_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 {
 	struct lmv_obd *lmv = &obd->u.lmv;
 	struct lmv_desc *desc;
+	struct lnet_process_id lnet_id;
+	int i = 0;
 	int rc;
 
 	if (LUSTRE_CFG_BUFLEN(lcfg, 1) < 1) {
@@ -1275,13 +1284,35 @@ static int lmv_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 	obd_str2uuid(&lmv->desc.ld_uuid, desc->ld_uuid.uuid);
 	lmv->desc.ld_tgt_count = 0;
 	lmv->desc.ld_active_tgt_count = 0;
-	lmv->desc.ld_qos_maxage = 60;
+	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);
 
+	/* Set up allocation policy (QoS and RR) */
+	INIT_LIST_HEAD(&lmv->lmv_qos.lq_svr_list);
+	init_rwsem(&lmv->lmv_qos.lq_rw_sem);
+	lmv->lmv_qos.lq_dirty = 1;
+	lmv->lmv_qos.lq_rr.lqr_dirty = 1;
+	lmv->lmv_qos.lq_reset = 1;
+	/* Default priority is toward free space balance */
+	lmv->lmv_qos.lq_prio_free = 232;
+	/* Default threshold for rr (roughly 17%) */
+	lmv->lmv_qos.lq_threshold_rr = 43;
+
+	/*
+	 * 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;
+		}
+	}
+
 	rc = lmv_tunables_init(obd);
 	if (rc)
 		CWARN("%s: error adding LMV sysfs/debugfs files: rc = %d\n",
@@ -1462,6 +1493,7 @@ static int lmv_statfs_update(void *cookie, int rc)
 		tgt->ltd_statfs = *osfs;
 		tgt->ltd_statfs_age = ktime_get_seconds();
 		spin_unlock(&lmv->lmv_lock);
+		lmv->lmv_qos.lq_dirty = 1;
 	}
 
 	return rc;
@@ -1541,7 +1573,7 @@ static int lmv_getattr(struct obd_export *exp, struct md_op_data *op_data,
 		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;
 	}
 
@@ -1585,17 +1617,6 @@ static int lmv_close(struct obd_export *exp, struct md_op_data *op_data,
 	return md_close(tgt->ltd_exp, op_data, mod, request);
 }
 
-static struct lmv_tgt_desc *lmv_locate_tgt_qos(struct lmv_obd *lmv, u32 *mdt)
-{
-	static unsigned int rr_index;
-
-	/* locate MDT round-robin is the first step */
-	*mdt = rr_index % lmv->tgts_size;
-	rr_index++;
-
-	return lmv->tgts[*mdt];
-}
-
 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,
@@ -1609,7 +1630,7 @@ static struct lmv_tgt_desc *lmv_locate_tgt_qos(struct lmv_obd *lmv, u32 *mdt)
 		if (IS_ERR(tgt))
 			return tgt;
 
-		*mds = tgt->ltd_idx;
+		*mds = tgt->ltd_index;
 		return tgt;
 	}
 
@@ -1698,12 +1719,18 @@ struct lmv_tgt_desc *
 		   lmv_dir_space_hashed(op_data->op_default_mea1) &&
 		   !lmv_dir_striped(lsm)) {
 		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 when mkdir under dir with "space" hash,
 		 * this means the cached statfs may be stale, and current mkdir
 		 * may not follow QoS accurately, but it's not serious, and it
 		 * avoids periodic statfs when client doesn't mkdir under
 		 * "space" hashed directories.
+		 *
+		 * TODO: after MDT support QoS object allocation, also update
+		 * statfs for 'lfs mkdir -i -1 ...", currently it's done in user
+		 * space.
 		 */
 		if (!IS_ERR(tgt)) {
 			struct obd_device *obd;
@@ -1823,7 +1850,7 @@ int lmv_create(struct obd_export *exp, struct md_op_data *op_data,
 		if (IS_ERR(tgt))
 			return PTR_ERR(tgt);
 
-		op_data->op_mds = tgt->ltd_idx;
+		op_data->op_mds = tgt->ltd_index;
 	}
 
 	CDEBUG(D_INODE, "CREATE obj " DFID " -> mds #%x\n",
@@ -1858,7 +1885,7 @@ int lmv_create(struct obd_export *exp, struct md_op_data *op_data,
 		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);
 
 	return md_enqueue(tgt->ltd_exp, einfo, policy, op_data, lockh,
 			  extra_lock_flags);
@@ -1881,7 +1908,7 @@ int lmv_create(struct obd_export *exp, struct md_op_data *op_data,
 
 	CDEBUG(D_INODE, "GETATTR_NAME for %*s on " DFID " -> mds #%u\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 == -ENOENT && lmv_dir_retry_check_update(op_data)) {
@@ -1935,7 +1962,7 @@ static int lmv_early_cancel(struct obd_export *exp, struct lmv_tgt_desc *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,
@@ -1981,7 +2008,7 @@ 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;
@@ -2075,7 +2102,7 @@ static int lmv_migrate(struct obd_export *exp, struct md_op_data *op_data,
 		return PTR_ERR(child_tgt);
 
 	if (!S_ISDIR(op_data->op_mode) && tp_tgt)
-		rc = __lmv_fid_alloc(lmv, &target_fid, tp_tgt->ltd_idx);
+		rc = __lmv_fid_alloc(lmv, &target_fid, tp_tgt->ltd_index);
 	else
 		rc = lmv_fid_alloc(NULL, exp, &target_fid, op_data);
 	if (rc)
@@ -2101,7 +2128,7 @@ static int lmv_migrate(struct obd_export *exp, struct md_op_data *op_data,
 	}
 
 	/* cancel UPDATE lock of parent master object */
-	rc = lmv_early_cancel(exp, parent_tgt, op_data, tgt->ltd_idx, LCK_EX,
+	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;
@@ -2126,14 +2153,14 @@ static int lmv_migrate(struct obd_export *exp, struct md_op_data *op_data,
 	op_data->op_fid4 = target_fid;
 
 	/* cancel UPDATE locks of target parent */
-	rc = lmv_early_cancel(exp, tp_tgt, op_data, tgt->ltd_idx, LCK_EX,
+	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_idx,
+		rc = lmv_early_cancel(exp, sp_tgt, op_data, tgt->ltd_index,
 				      LCK_EX, MDS_INODELOCK_LOOKUP,
 				      MF_MDC_CANCEL_FID3);
 		if (rc)
@@ -2141,7 +2168,7 @@ static int lmv_migrate(struct obd_export *exp, struct md_op_data *op_data,
 	}
 
 	/* cancel ELC locks of source */
-	rc = lmv_early_cancel(exp, child_tgt, op_data, tgt->ltd_idx, LCK_EX,
+	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;
@@ -2201,7 +2228,7 @@ static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
 	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_idx, LCK_EX,
+	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;
@@ -2210,7 +2237,7 @@ static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
 		/* cancel LOOKUP lock of target on target parent */
 		if (tgt != tp_tgt) {
 			rc = lmv_early_cancel(exp, tp_tgt, op_data,
-					      tgt->ltd_idx, LCK_EX,
+					      tgt->ltd_index, LCK_EX,
 					      MDS_INODELOCK_LOOKUP,
 					      MF_MDC_CANCEL_FID4);
 			if (rc != 0)
@@ -2224,7 +2251,7 @@ static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
 			return PTR_ERR(src_tgt);
 
 		/* cancel ELC locks of source */
-		rc = lmv_early_cancel(exp, src_tgt, op_data, tgt->ltd_idx,
+		rc = lmv_early_cancel(exp, src_tgt, op_data, tgt->ltd_index,
 				      LCK_EX, MDS_INODELOCK_ELC,
 				      MF_MDC_CANCEL_FID3);
 		if (rc != 0)
@@ -2239,7 +2266,7 @@ static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
 		return PTR_ERR(sp_tgt);
 
 	/* cancel UPDATE locks of source parent */
-	rc = lmv_early_cancel(exp, sp_tgt, op_data, tgt->ltd_idx, LCK_EX,
+	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;
@@ -2248,7 +2275,7 @@ static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
 		/* cancel LOOKUP lock of source on source parent */
 		if (src_tgt != sp_tgt) {
 			rc = lmv_early_cancel(exp, sp_tgt, op_data,
-					      tgt->ltd_idx, LCK_EX,
+					      tgt->ltd_index, LCK_EX,
 					      MDS_INODELOCK_LOOKUP,
 					      MF_MDC_CANCEL_FID3);
 			if (rc != 0)
@@ -2293,7 +2320,7 @@ static int lmv_rename(struct obd_export *exp, struct md_op_data *op_data,
 		/* cancel LOOKUP lock of target on target parent */
 		if (tgt != tp_tgt) {
 			rc = lmv_early_cancel(exp, tp_tgt, op_data,
-					      tgt->ltd_idx, LCK_EX,
+					      tgt->ltd_index, LCK_EX,
 					      MDS_INODELOCK_LOOKUP,
 					      MF_MDC_CANCEL_FID4);
 			if (rc != 0)
@@ -2781,17 +2808,18 @@ static int lmv_unlink(struct obd_export *exp, struct md_op_data *op_data,
 	op_data->op_flags |= MF_MDC_CANCEL_FID1 | MF_MDC_CANCEL_FID3;
 
 	if (parent_tgt != tgt)
-		rc = lmv_early_cancel(exp, parent_tgt, op_data, tgt->ltd_idx,
+		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,
+	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 == -ENOENT && lmv_dir_retry_check_update(op_data)) {
diff --git a/fs/lustre/lmv/lmv_qos.c b/fs/lustre/lmv/lmv_qos.c
new file mode 100644
index 0000000..e323398
--- /dev/null
+++ b/fs/lustre/lmv/lmv_qos.c
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * GPL HEADER END
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ *
+ * lustre/lmv/lmv_qos.c
+ *
+ * LMV QoS.
+ * These are the only exported functions, they provide some generic
+ * infrastructure for object allocation QoS
+ *
+ */
+
+#define DEBUG_SUBSYSTEM S_LMV
+
+#include <asm/div64.h>
+#include <uapi/linux/lustre/lustre_idl.h>
+#include <lustre_swab.h>
+#include <obd_class.h>
+
+#include "lmv_internal.h"
+
+static inline u64 tgt_statfs_bavail(struct lu_tgt_desc *tgt)
+{
+	struct obd_statfs *statfs = &tgt->ltd_statfs;
+
+	return statfs->os_bavail * statfs->os_bsize;
+}
+
+static inline u64 tgt_statfs_iavail(struct lu_tgt_desc *tgt)
+{
+	return tgt->ltd_statfs.os_ffree;
+}
+
+/**
+ * Calculate penalties per-tgt and per-server
+ *
+ * Re-calculate penalties when the configuration changes, active targets
+ * change and after statfs refresh (all these are reflected by lq_dirty flag).
+ * On every MDT and MDS: decay the penalty by half for every 8x the update
+ * interval that the device has been idle. That gives lots of time for the
+ * statfs information to be updated (which the penalty is only a proxy for),
+ * and avoids penalizing MDS/MDTs under light load.
+ * See lmv_qos_calc_weight() for how penalties are factored into the weight.
+ *
+ * @lmv			LMV device
+ *
+ * Return:		0 on success
+ *			-EAGAIN	if the number of MDTs isn't enough or all
+ *			MDT spaces are almost the same
+ */
+static int lmv_qos_calc_ppts(struct lmv_obd *lmv)
+{
+	struct lu_qos *qos = &lmv->lmv_qos;
+	struct lu_tgt_desc *tgt;
+	struct lu_svr_qos *svr;
+	u64 ba_max, ba_min, ba;
+	u64 ia_max, ia_min, ia;
+	u32 num_active;
+	unsigned int i;
+	int prio_wide;
+	time64_t now, age;
+	u32 maxage = lmv->desc.ld_qos_maxage;
+	int rc = 0;
+
+
+	if (!qos->lq_dirty)
+		goto out;
+
+	num_active = lmv->desc.ld_active_tgt_count;
+	if (num_active < 2) {
+		rc = -EAGAIN;
+		goto out;
+	}
+
+	/* find bavail on each server */
+	list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
+		svr->lsq_bavail = 0;
+		svr->lsq_iavail = 0;
+	}
+	qos->lq_active_svr_count = 0;
+
+	/*
+	 * How badly user wants to select targets "widely" (not recently chosen
+	 * and not on recent MDS's).  As opposed to "freely" (free space avail.)
+	 * 0-256
+	 */
+	prio_wide = 256 - qos->lq_prio_free;
+
+	ba_min = (u64)(-1);
+	ba_max = 0;
+	ia_min = (u64)(-1);
+	ia_max = 0;
+	now = ktime_get_real_seconds();
+
+	/* Calculate server penalty per object */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[i];
+		if (!tgt || !tgt->ltd_exp || !tgt->ltd_active)
+			continue;
+
+		/* bavail >> 16 to avoid overflow */
+		ba = tgt_statfs_bavail(tgt) >> 16;
+		if (!ba)
+			continue;
+
+		ba_min = min(ba, ba_min);
+		ba_max = max(ba, ba_max);
+
+		/* iavail >> 8 to avoid overflow */
+		ia = tgt_statfs_iavail(tgt) >> 8;
+		if (!ia)
+			continue;
+
+		ia_min = min(ia, ia_min);
+		ia_max = max(ia, ia_max);
+
+		/* Count the number of usable MDS's */
+		if (tgt->ltd_qos.ltq_svr->lsq_bavail == 0)
+			qos->lq_active_svr_count++;
+		tgt->ltd_qos.ltq_svr->lsq_bavail += ba;
+		tgt->ltd_qos.ltq_svr->lsq_iavail += ia;
+
+		/*
+		 * per-MDT penalty is
+		 * prio * bavail * iavail / (num_tgt - 1) / 2
+		 */
+		tgt->ltd_qos.ltq_penalty_per_obj = prio_wide * ba * ia;
+		do_div(tgt->ltd_qos.ltq_penalty_per_obj, num_active - 1);
+		tgt->ltd_qos.ltq_penalty_per_obj >>= 1;
+
+		age = (now - tgt->ltd_qos.ltq_used) >> 3;
+		if (qos->lq_reset || age > 32 * maxage)
+			tgt->ltd_qos.ltq_penalty = 0;
+		else if (age > maxage)
+			/* Decay tgt penalty. */
+			tgt->ltd_qos.ltq_penalty >>= (age / maxage);
+	}
+
+	num_active = qos->lq_active_svr_count;
+	if (num_active < 2) {
+		/*
+		 * If there's only 1 MDS, we can't penalize it, so instead
+		 * we have to double the MDT penalty
+		 */
+		num_active = 2;
+		for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+			tgt = lmv->tgts[i];
+			if (!tgt || !tgt->ltd_exp || !tgt->ltd_active)
+				continue;
+
+			tgt->ltd_qos.ltq_penalty_per_obj <<= 1;
+		}
+	}
+
+	/*
+	 * Per-MDS penalty is
+	 * prio * bavail * iavail / server_tgts / (num_svr - 1) / 2
+	 */
+	list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
+		ba = svr->lsq_bavail;
+		ia = svr->lsq_iavail;
+		svr->lsq_penalty_per_obj = prio_wide * ba  * ia;
+		do_div(ba, svr->lsq_tgt_count * (num_active - 1));
+		svr->lsq_penalty_per_obj >>= 1;
+
+		age = (now - svr->lsq_used) >> 3;
+		if (qos->lq_reset || age > 32 * maxage)
+			svr->lsq_penalty = 0;
+		else if (age > maxage)
+			/* Decay server penalty. */
+			svr->lsq_penalty >>= age / maxage;
+	}
+
+	qos->lq_dirty = 0;
+	qos->lq_reset = 0;
+
+	/*
+	 * If each MDT has almost same free space, do rr allocation for better
+	 * creation performance
+	 */
+	qos->lq_same_space = 0;
+	if ((ba_max * (256 - qos->lq_threshold_rr)) >> 8 < ba_min &&
+	    (ia_max * (256 - qos->lq_threshold_rr)) >> 8 < ia_min) {
+		qos->lq_same_space = 1;
+		/* Reset weights for the next time we enter qos mode */
+		qos->lq_reset = 1;
+	}
+	rc = 0;
+
+out:
+	if (!rc && qos->lq_same_space)
+		return -EAGAIN;
+
+	return rc;
+}
+
+static inline bool lmv_qos_is_usable(struct lmv_obd *lmv)
+{
+	if (!lmv->lmv_qos.lq_dirty && lmv->lmv_qos.lq_same_space)
+		return false;
+
+	if (lmv->desc.ld_active_tgt_count < 2)
+		return false;
+
+	return true;
+}
+
+/**
+ * Calculate weight for a given MDT.
+ *
+ * The final MDT weight is bavail >> 16 * iavail >> 8 minus the MDT and MDS
+ * penalties.  See lmv_qos_calc_ppts() for how penalties are calculated.
+ *
+ * \param[in] tgt	MDT target descriptor
+ */
+static void lmv_qos_calc_weight(struct lu_tgt_desc *tgt)
+{
+	struct lu_tgt_qos *ltq = &tgt->ltd_qos;
+	u64 temp, temp2;
+
+	temp = (tgt_statfs_bavail(tgt) >> 16) * (tgt_statfs_iavail(tgt) >> 8);
+	temp2 = ltq->ltq_penalty + ltq->ltq_svr->lsq_penalty;
+	if (temp < temp2)
+		ltq->ltq_weight = 0;
+	else
+		ltq->ltq_weight = temp - temp2;
+}
+
+/**
+ * Re-calculate weights.
+ *
+ * The function is called when some target was used for a new object. In
+ * this case we should re-calculate all the weights to keep new allocations
+ * balanced well.
+ *
+ * \param[in] lmv	LMV device
+ * \param[in] tgt	target where a new object was placed
+ * \param[out] total_wt	new total weight for the pool
+ *
+ * \retval		0
+ */
+static int lmv_qos_used(struct lmv_obd *lmv, struct lu_tgt_desc *tgt,
+			u64 *total_wt)
+{
+	struct lu_tgt_qos *ltq;
+	struct lu_svr_qos *svr;
+	unsigned int i;
+
+	ltq = &tgt->ltd_qos;
+	LASSERT(ltq);
+
+	/* Don't allocate on this device anymore, until the next alloc_qos */
+	ltq->ltq_usable = 0;
+
+	svr = ltq->ltq_svr;
+
+	/*
+	 * Decay old penalty by half (we're adding max penalty, and don't
+	 * want it to run away.)
+	 */
+	ltq->ltq_penalty >>= 1;
+	svr->lsq_penalty >>= 1;
+
+	/* mark the MDS and MDT as recently used */
+	ltq->ltq_used = svr->lsq_used = ktime_get_real_seconds();
+
+	/* Set max penalties for this MDT and MDS */
+	ltq->ltq_penalty += ltq->ltq_penalty_per_obj *
+			    lmv->desc.ld_active_tgt_count;
+	svr->lsq_penalty += svr->lsq_penalty_per_obj *
+		lmv->lmv_qos.lq_active_svr_count;
+
+	/* Decrease all MDS penalties */
+	list_for_each_entry(svr, &lmv->lmv_qos.lq_svr_list, lsq_svr_list) {
+		if (svr->lsq_penalty < svr->lsq_penalty_per_obj)
+			svr->lsq_penalty = 0;
+		else
+			svr->lsq_penalty -= svr->lsq_penalty_per_obj;
+	}
+
+	*total_wt = 0;
+	/* Decrease all MDT penalties */
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		ltq = &lmv->tgts[i]->ltd_qos;
+		if (!tgt || !tgt->ltd_exp || !tgt->ltd_active)
+			continue;
+
+		if (ltq->ltq_penalty < ltq->ltq_penalty_per_obj)
+			ltq->ltq_penalty = 0;
+		else
+			ltq->ltq_penalty -= ltq->ltq_penalty_per_obj;
+
+		lmv_qos_calc_weight(lmv->tgts[i]);
+
+		/* Recalc the total weight of usable osts */
+		if (ltq->ltq_usable)
+			*total_wt += ltq->ltq_weight;
+
+		CDEBUG(D_OTHER,
+		       "recalc tgt %d usable=%d avail=%llu tgtppo=%llu tgtp=%llu svrppo=%llu svrp=%llu wt=%llu\n",
+		       i, ltq->ltq_usable,
+		       tgt_statfs_bavail(tgt) >> 10,
+		       ltq->ltq_penalty_per_obj >> 10,
+		       ltq->ltq_penalty >> 10,
+		       ltq->ltq_svr->lsq_penalty_per_obj >> 10,
+		       ltq->ltq_svr->lsq_penalty >> 10,
+		       ltq->ltq_weight >> 10);
+	}
+
+	return 0;
+}
+
+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 i;
+	int rc;
+
+	if (!lmv_qos_is_usable(lmv))
+		return ERR_PTR(-EAGAIN);
+
+	down_write(&lmv->lmv_qos.lq_rw_sem);
+
+	if (!lmv_qos_is_usable(lmv)) {
+		tgt = ERR_PTR(-EAGAIN);
+		goto unlock;
+	}
+
+	rc = lmv_qos_calc_ppts(lmv);
+	if (rc) {
+		tgt = ERR_PTR(rc);
+		goto unlock;
+	}
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[i];
+		if (!tgt)
+			continue;
+
+		tgt->ltd_qos.ltq_usable = 0;
+		if (!tgt->ltd_exp || !tgt->ltd_active)
+			continue;
+
+		tgt->ltd_qos.ltq_usable = 1;
+		lmv_qos_calc_weight(tgt);
+		total_weight += tgt->ltd_qos.ltq_weight;
+	}
+
+	if (total_weight) {
+#if BITS_PER_LONG == 32
+		/*
+		 * If total_weight > 32-bit, first generate the high
+		 * 32 bits of the random number, then add in the low
+		 * 32 bits (truncated to the upper limit, if needed)
+		 */
+		if (total_weight > 0xffffffffULL)
+			rand = (u64)(prandom_u32_max(
+				(unsigned int)(total_weight >> 32)) << 32;
+		else
+			rand = 0;
+
+		if (rand == (total_weight & 0xffffffff00000000ULL))
+			rand |= prandom_u32_max((unsigned int)total_weight);
+		else
+			rand |= prandom_u32();
+
+#else
+		rand = ((u64)prandom_u32() << 32 | prandom_u32()) %
+			total_weight;
+#endif
+	} else {
+		rand = 0;
+	}
+
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[i];
+
+		if (!tgt || !tgt->ltd_qos.ltq_usable)
+			continue;
+
+		cur_weight += tgt->ltd_qos.ltq_weight;
+		if (cur_weight < rand)
+			continue;
+
+		*mdt = tgt->ltd_index;
+		lmv_qos_used(lmv, tgt, &total_weight);
+		rc = 0;
+		goto unlock;
+	}
+
+	/* no proper target found */
+	tgt = ERR_PTR(-EAGAIN);
+	goto unlock;
+unlock:
+	up_write(&lmv->lmv_qos.lq_rw_sem);
+
+	return tgt;
+}
+
+struct lu_tgt_desc *lmv_locate_tgt_rr(struct lmv_obd *lmv, u32 *mdt)
+{
+	struct lu_tgt_desc *tgt;
+	int i;
+
+	spin_lock(&lmv->lmv_qos.lq_rr.lqr_alloc);
+	for (i = 0; i < lmv->desc.ld_tgt_count; i++) {
+		tgt = lmv->tgts[(i + lmv->lmv_qos_rr_index) %
+				lmv->desc.ld_tgt_count];
+		if (tgt && tgt->ltd_exp && tgt->ltd_active) {
+			*mdt = tgt->ltd_index;
+			lmv->lmv_qos_rr_index =
+				(i + lmv->lmv_qos_rr_index + 1) %
+				lmv->desc.ld_tgt_count;
+			spin_unlock(&lmv->lmv_qos.lq_rr.lqr_alloc);
+
+			return tgt;
+		}
+	}
+	spin_unlock(&lmv->lmv_qos.lq_rr.lqr_alloc);
+
+	return ERR_PTR(-ENODEV);
+}
diff --git a/fs/lustre/lmv/lproc_lmv.c b/fs/lustre/lmv/lproc_lmv.c
index 170ed564..659ebeb 100644
--- a/fs/lustre/lmv/lproc_lmv.c
+++ b/fs/lustre/lmv/lproc_lmv.c
@@ -76,6 +76,109 @@ static ssize_t desc_uuid_show(struct kobject *kobj, struct attribute *attr,
 }
 LUSTRE_RO_ATTR(desc_uuid);
 
+static ssize_t qos_maxage_show(struct kobject *kobj,
+			       struct attribute *attr,
+			       char *buf)
+{
+	struct obd_device *dev = container_of(kobj, struct obd_device,
+					      obd_kset.kobj);
+
+	return sprintf(buf, "%u\n", dev->u.lmv.desc.ld_qos_maxage);
+}
+
+static ssize_t qos_maxage_store(struct kobject *kobj,
+				struct attribute *attr,
+				const char *buffer,
+				size_t count)
+{
+	struct obd_device *dev = container_of(kobj, struct obd_device,
+					      obd_kset.kobj);
+	unsigned int val;
+	int rc;
+
+	rc = kstrtouint(buffer, 0, &val);
+	if (rc)
+		return rc;
+
+	dev->u.lmv.desc.ld_qos_maxage = val;
+
+	return count;
+}
+LUSTRE_RW_ATTR(qos_maxage);
+
+static ssize_t qos_prio_free_show(struct kobject *kobj,
+				  struct attribute *attr,
+				  char *buf)
+{
+	struct obd_device *dev = container_of(kobj, struct obd_device,
+					      obd_kset.kobj);
+
+	return sprintf(buf, "%u%%\n",
+		       (dev->u.lmv.lmv_qos.lq_prio_free * 100 + 255) >> 8);
+}
+
+static ssize_t qos_prio_free_store(struct kobject *kobj,
+				   struct attribute *attr,
+				   const char *buffer,
+				   size_t count)
+{
+	struct obd_device *dev = container_of(kobj, struct obd_device,
+					      obd_kset.kobj);
+	struct lmv_obd *lmv = &dev->u.lmv;
+	unsigned int val;
+	int rc;
+
+	rc = kstrtouint(buffer, 0, &val);
+	if (rc)
+		return rc;
+
+	if (val > 100)
+		return -EINVAL;
+
+	lmv->lmv_qos.lq_prio_free = (val << 8) / 100;
+	lmv->lmv_qos.lq_dirty = 1;
+	lmv->lmv_qos.lq_reset = 1;
+
+	return count;
+}
+LUSTRE_RW_ATTR(qos_prio_free);
+
+static ssize_t qos_threshold_rr_show(struct kobject *kobj,
+				     struct attribute *attr,
+				     char *buf)
+{
+	struct obd_device *dev = container_of(kobj, struct obd_device,
+					      obd_kset.kobj);
+
+	return sprintf(buf, "%u%%\n",
+		       (dev->u.lmv.lmv_qos.lq_threshold_rr * 100 + 255) >> 8);
+}
+
+static ssize_t qos_threshold_rr_store(struct kobject *kobj,
+				      struct attribute *attr,
+				      const char *buffer,
+				      size_t count)
+{
+	struct obd_device *dev = container_of(kobj, struct obd_device,
+					      obd_kset.kobj);
+	struct lmv_obd *lmv = &dev->u.lmv;
+	unsigned int val;
+	int rc;
+
+	rc = kstrtouint(buffer, 0, &val);
+	if (rc)
+		return rc;
+
+	if (val > 100)
+		return -EINVAL;
+
+	lmv->lmv_qos.lq_threshold_rr = (val << 8) / 100;
+	lmv->lmv_qos.lq_dirty = 1;
+
+	return count;
+}
+LUSTRE_RW_ATTR(qos_threshold_rr);
+
 static void *lmv_tgt_seq_start(struct seq_file *p, loff_t *pos)
 {
 	struct obd_device *dev = p->private;
@@ -117,7 +220,7 @@ static int lmv_tgt_seq_show(struct seq_file *p, void *v)
 		return 0;
 
 	seq_printf(p, "%u: %s %sACTIVE\n",
-		   tgt->ltd_idx, tgt->ltd_uuid.uuid,
+		   tgt->ltd_index, tgt->ltd_uuid.uuid,
 		   tgt->ltd_active ? "" : "IN");
 	return 0;
 }
@@ -156,6 +259,9 @@ static int lmv_target_seq_open(struct inode *inode, struct file *file)
 	&lustre_attr_activeobd.attr,
 	&lustre_attr_desc_uuid.attr,
 	&lustre_attr_numobd.attr,
+	&lustre_attr_qos_maxage.attr,
+	&lustre_attr_qos_prio_free.attr,
+	&lustre_attr_qos_threshold_rr.attr,
 	NULL,
 };
 
diff --git a/fs/lustre/obdclass/Makefile b/fs/lustre/obdclass/Makefile
index 25d2e1d..6d762ed 100644
--- a/fs/lustre/obdclass/Makefile
+++ b/fs/lustre/obdclass/Makefile
@@ -8,4 +8,4 @@ obdclass-y := llog.o llog_cat.o llog_obd.o llog_swab.o class_obd.o \
 	      lustre_handles.o lustre_peer.o statfs_pack.o linkea.o \
 	      obdo.o obd_config.o obd_mount.o lu_object.o lu_ref.o \
 	      cl_object.o cl_page.o cl_lock.o cl_io.o kernelcomm.o \
-	      jobid.o integrity.o obd_cksum.o
+	      jobid.o integrity.o obd_cksum.o lu_qos.o
diff --git a/fs/lustre/obdclass/lu_qos.c b/fs/lustre/obdclass/lu_qos.c
new file mode 100644
index 0000000..4ee3f59
--- /dev/null
+++ b/fs/lustre/obdclass/lu_qos.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * GPL HEADER END
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ *
+ * lustre/obdclass/lu_qos.c
+ *
+ * Lustre QoS.
+ * These are the only exported functions, they provide some generic
+ * infrastructure for object allocation QoS
+ *
+ */
+
+#define DEBUG_SUBSYSTEM S_CLASS
+
+#include <linux/module.h>
+#include <linux/list.h>
+#include <obd_class.h>
+#include <obd_support.h>
+#include <lustre_disk.h>
+#include <lustre_fid.h>
+#include <lu_object.h>
+
+/**
+ * Add a new target to Quality of Service (QoS) target table.
+ *
+ * Add a new MDT/OST target to the structure representing an OSS. Resort the
+ * list of known MDSs/OSSs by the number of MDTs/OSTs attached to each MDS/OSS.
+ * The MDS/OSS list is protected internally and no external locking is required.
+ *
+ * @qos		lu_qos data
+ * @ltd		target description
+ *
+ * Return:	0 on success
+ *		-ENOMEM	on error
+ */
+int lqos_add_tgt(struct lu_qos *qos, struct lu_tgt_desc *ltd)
+{
+	struct lu_svr_qos *svr = NULL;
+	struct lu_svr_qos *tempsvr;
+	struct obd_export *exp = ltd->ltd_exp;
+	int found = 0;
+	u32 id = 0;
+	int rc = 0;
+
+	down_write(&qos->lq_rw_sem);
+	/*
+	 * a bit hacky approach to learn NID of corresponding connection
+	 * but there is no official API to access information like this
+	 * with OSD API.
+	 */
+	list_for_each_entry(svr, &qos->lq_svr_list, lsq_svr_list) {
+		if (obd_uuid_equals(&svr->lsq_uuid,
+				    &exp->exp_connection->c_remote_uuid)) {
+			found++;
+			break;
+		}
+		if (svr->lsq_id > id)
+			id = svr->lsq_id;
+	}
+
+	if (!found) {
+		svr = kmalloc(sizeof(*svr), GFP_NOFS);
+		if (!svr) {
+			rc = -ENOMEM;
+			goto out;
+		}
+		memcpy(&svr->lsq_uuid, &exp->exp_connection->c_remote_uuid,
+		       sizeof(svr->lsq_uuid));
+		++id;
+		svr->lsq_id = id;
+	} else {
+		/* Assume we have to move this one */
+		list_del(&svr->lsq_svr_list);
+	}
+
+	svr->lsq_tgt_count++;
+	ltd->ltd_qos.ltq_svr = svr;
+
+	CDEBUG(D_OTHER, "add tgt %s to server %s (%d targets)\n",
+	       obd_uuid2str(&ltd->ltd_uuid), obd_uuid2str(&svr->lsq_uuid),
+	       svr->lsq_tgt_count);
+
+	/*
+	 * Add sorted by # of tgts.  Find the first entry that we're
+	 * bigger than...
+	 */
+	list_for_each_entry(tempsvr, &qos->lq_svr_list, lsq_svr_list) {
+		if (svr->lsq_tgt_count > tempsvr->lsq_tgt_count)
+			break;
+	}
+	/*
+	 * ...and add before it.  If we're the first or smallest, tempsvr
+	 * points to the list head, and we add to the end.
+	 */
+	list_add_tail(&svr->lsq_svr_list, &tempsvr->lsq_svr_list);
+
+	qos->lq_dirty = 1;
+	qos->lq_rr.lqr_dirty = 1;
+
+out:
+	up_write(&qos->lq_rw_sem);
+	return rc;
+}
+EXPORT_SYMBOL(lqos_add_tgt);
+
+/**
+ * Remove MDT/OST target from QoS table.
+ *
+ * Removes given MDT/OST target from QoS table and releases related
+ * MDS/OSS structure if no target remain on the MDS/OSS.
+ *
+ * @qos		lu_qos data
+ * @ltd		target description
+ *
+ * Return:	0 on success
+ *		-ENOENT	if no server was found
+ */
+int lqos_del_tgt(struct lu_qos *qos, struct lu_tgt_desc *ltd)
+{
+	struct lu_svr_qos *svr;
+	int rc = 0;
+
+	down_write(&qos->lq_rw_sem);
+	svr = ltd->ltd_qos.ltq_svr;
+	if (!svr) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	svr->lsq_tgt_count--;
+	if (svr->lsq_tgt_count == 0) {
+		CDEBUG(D_OTHER, "removing server %s\n",
+		       obd_uuid2str(&svr->lsq_uuid));
+		list_del(&svr->lsq_svr_list);
+		ltd->ltd_qos.ltq_svr = NULL;
+		kfree(svr);
+	}
+
+	qos->lq_dirty = 1;
+	qos->lq_rr.lqr_dirty = 1;
+out:
+	up_write(&qos->lq_rw_sem);
+	return rc;
+}
+EXPORT_SYMBOL(lqos_del_tgt);
diff --git a/include/uapi/linux/lustre/lustre_idl.h b/include/uapi/linux/lustre/lustre_idl.h
index 86395b7..a26f3ae 100644
--- a/include/uapi/linux/lustre/lustre_idl.h
+++ b/include/uapi/linux/lustre/lustre_idl.h
@@ -1931,6 +1931,8 @@ struct mdt_rec_reint {
 	__u16		rr_padding_4; /* also fix lustre_swab_mdt_rec_reint */
 };
 
+#define LMV_DESC_QOS_MAXAGE_DEFAULT 60  /* Seconds */
+
 /* lmv structures */
 struct lmv_desc {
 	__u32 ld_tgt_count;		/* how many MDS's */
