X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fosp%2Fosp_trans.c;h=9686863b7abfa1ab1c9a60ad4d09c969143dcae0;hp=6d0067aecbf6961ff1be79376d2e5c428957f3d3;hb=f32fbf189fab57202810a9a47343a14c6c3ead95;hpb=2fe22edfe3c365b5c270050fdeed0a86fa74a919

diff --git a/lustre/osp/osp_trans.c b/lustre/osp/osp_trans.c
index 6d0067a..9686863 100644
--- a/lustre/osp/osp_trans.c
+++ b/lustre/osp/osp_trans.c
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2014, Intel Corporation.
+ * Copyright (c) 2014, 2017, Intel Corporation.
  */
 /*
  * lustre/osp/osp_trans.c
@@ -66,6 +66,7 @@
 
 #define DEBUG_SUBSYSTEM S_MDS
 
+#include <lustre_net.h>
 #include "osp_internal.h"
 
 /**
@@ -76,6 +77,7 @@ struct osp_update_args {
 	atomic_t		 *oaua_count;
 	wait_queue_head_t	 *oaua_waitq;
 	bool			  oaua_flow_control;
+	const struct lu_env	 *oaua_update_env;
 };
 
 /**
@@ -95,25 +97,72 @@ struct osp_update_callback {
 	osp_update_interpreter_t	ouc_interpreter;
 };
 
-static struct object_update_request *object_update_request_alloc(size_t size)
+/**
+ * Allocate new update request
+ *
+ * Allocate new update request and insert it to the req_update_list.
+ *
+ * \param [in] our	osp_udate_request where to create a new
+ *                      update request
+ *
+ * \retval	0 if creation succeeds.
+ * \retval	negative errno if creation fails.
+ */
+int osp_object_update_request_create(struct osp_update_request *our,
+				     size_t size)
 {
+	struct osp_update_request_sub *ours;
 	struct object_update_request *ourq;
 
+	OBD_ALLOC_PTR(ours);
+	if (ours == NULL)
+		return -ENOMEM;
+
+	/* The object update request will be added to an SG list for
+	 * bulk transfer. Some IB HW cannot handle partial pages in SG
+	 * lists (since they create gaps in memory regions) so we
+	 * round the size up to the next multiple of PAGE_SIZE. See
+	 * LU-9983. */
+	LASSERT(size > 0);
+	size = round_up(size, PAGE_SIZE);
 	OBD_ALLOC_LARGE(ourq, size);
-	if (ourq == NULL)
-		return ERR_PTR(-ENOMEM);
+	if (ourq == NULL) {
+		OBD_FREE_PTR(ours);
+		return -ENOMEM;
+	}
 
 	ourq->ourq_magic = UPDATE_REQUEST_MAGIC;
 	ourq->ourq_count = 0;
+	ours->ours_req = ourq;
+	ours->ours_req_size = size;
+	INIT_LIST_HEAD(&ours->ours_list);
+	list_add_tail(&ours->ours_list, &our->our_req_list);
+	our->our_req_nr++;
 
-	return ourq;
+	return 0;
 }
 
-static void object_update_request_free(struct object_update_request *ourq,
-				       size_t ourq_size)
+/**
+ * Get current update request
+ *
+ * Get current object update request from our_req_list in
+ * osp_update_request, because we always insert the new update
+ * request in the last position, so the last update request
+ * in the list will be the current update req.
+ *
+ * \param[in] our	osp update request where to get the
+ *                      current object update.
+ *
+ * \retval		the current object update.
+ **/
+struct osp_update_request_sub *
+osp_current_object_update_request(struct osp_update_request *our)
 {
-	if (ourq != NULL)
-		OBD_FREE_LARGE(ourq, ourq_size);
+	if (list_empty(&our->our_req_list))
+		return NULL;
+
+	return list_entry(our->our_req_list.prev, struct osp_update_request_sub,
+			  ours_list);
 }
 
 /**
@@ -130,35 +179,67 @@ static void object_update_request_free(struct object_update_request *ourq,
  */
 struct osp_update_request *osp_update_request_create(struct dt_device *dt)
 {
-	struct osp_update_request *osp_update_req;
-	struct object_update_request *ourq;
+	struct osp_update_request *our;
+	int rc;
 
-	OBD_ALLOC_PTR(osp_update_req);
-	if (osp_update_req == NULL)
+	OBD_ALLOC_PTR(our);
+	if (our == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	ourq = object_update_request_alloc(OUT_UPDATE_INIT_BUFFER_SIZE);
-	if (IS_ERR(ourq)) {
-		OBD_FREE_PTR(osp_update_req);
-		return ERR_CAST(ourq);
-	}
-
-	osp_update_req->our_req = ourq;
-	osp_update_req->our_req_size = OUT_UPDATE_INIT_BUFFER_SIZE;
+	INIT_LIST_HEAD(&our->our_req_list);
+	INIT_LIST_HEAD(&our->our_cb_items);
+	INIT_LIST_HEAD(&our->our_list);
+	INIT_LIST_HEAD(&our->our_invalidate_cb_list);
+	spin_lock_init(&our->our_list_lock);
 
-	INIT_LIST_HEAD(&osp_update_req->our_cb_items);
-	INIT_LIST_HEAD(&osp_update_req->our_list);
-
-	return osp_update_req;
+	rc = osp_object_update_request_create(our, PAGE_SIZE);
+	if (rc != 0) {
+		OBD_FREE_PTR(our);
+		return ERR_PTR(rc);
+	}
+	return our;
 }
 
-void osp_update_request_destroy(struct osp_update_request *our)
+void osp_update_request_destroy(const struct lu_env *env,
+				struct osp_update_request *our)
 {
+	struct osp_update_request_sub *ours;
+	struct osp_update_request_sub *tmp;
+
 	if (our == NULL)
 		return;
 
-	object_update_request_free(our->our_req,
-				   our->our_req_size);
+	list_for_each_entry_safe(ours, tmp, &our->our_req_list, ours_list) {
+		list_del(&ours->ours_list);
+		if (ours->ours_req != NULL)
+			OBD_FREE_LARGE(ours->ours_req, ours->ours_req_size);
+		OBD_FREE_PTR(ours);
+	}
+
+	if (!list_empty(&our->our_invalidate_cb_list)) {
+		struct lu_env lenv;
+		struct osp_object *obj;
+		struct osp_object *next;
+
+		if (env == NULL) {
+			lu_env_init(&lenv, LCT_MD_THREAD | LCT_DT_THREAD);
+			env = &lenv;
+		}
+
+		list_for_each_entry_safe(obj, next,
+					 &our->our_invalidate_cb_list,
+					 opo_invalidate_cb_list) {
+			spin_lock(&obj->opo_lock);
+			list_del_init(&obj->opo_invalidate_cb_list);
+			spin_unlock(&obj->opo_lock);
+
+			dt_object_put(env, &obj->opo_obj);
+		}
+
+		if (env == &lenv)
+			lu_env_fini(&lenv);
+	}
+
 	OBD_FREE_PTR(our);
 }
 
@@ -175,12 +256,13 @@ object_update_request_dump(const struct object_update_request *ourq,
 
 		update = object_update_request_get(ourq, i, &size);
 		LASSERT(update != NULL);
-		CDEBUG(mask, "i = %u fid = "DFID" op = %s master = %u"
-		       "params = %d batchid = "LPU64" size = %zu\n",
+		CDEBUG(mask, "i = %u fid = "DFID" op = %s "
+		       "params = %d batchid = %llu size = %zu repsize %u\n",
 		       i, PFID(&update->ou_fid),
 		       update_op_str(update->ou_type),
-		       update->ou_master_index, update->ou_params_count,
-		       update->ou_batchid, size);
+		       update->ou_params_count,
+		       update->ou_batchid, size,
+		       (unsigned)update->ou_result_size);
 
 		total_size += size;
 	}
@@ -189,7 +271,263 @@ object_update_request_dump(const struct object_update_request *ourq,
 	       ourq->ourq_magic, ourq->ourq_count, total_size);
 }
 
-static void osp_trans_stop_cb(struct osp_thandle *oth, int result)
+/**
+ * Prepare inline update request
+ *
+ * Prepare OUT update ptlrpc inline request, and the request usually includes
+ * one update buffer, which does not need bulk transfer.
+ *
+ * \param[in] env	execution environment
+ * \param[in] req	ptlrpc request
+ * \param[in] ours	sub osp_update_request to be packed
+ *
+ * \retval		0 if packing succeeds
+ * \retval		negative errno if packing fails
+ */
+int osp_prep_inline_update_req(const struct lu_env *env,
+			       struct ptlrpc_request *req,
+			       struct osp_update_request *our,
+			       int repsize)
+{
+	struct osp_update_request_sub *ours;
+	struct out_update_header *ouh;
+	__u32 update_req_size;
+	int rc;
+
+	ours = list_entry(our->our_req_list.next,
+			  struct osp_update_request_sub, ours_list);
+	update_req_size = object_update_request_size(ours->ours_req);
+	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_HEADER, RCL_CLIENT,
+			     update_req_size + sizeof(*ouh));
+
+	rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, OUT_UPDATE);
+	if (rc != 0)
+		RETURN(rc);
+
+	ouh = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE_HEADER);
+	ouh->ouh_magic = OUT_UPDATE_HEADER_MAGIC;
+	ouh->ouh_count = 1;
+	ouh->ouh_inline_length = update_req_size;
+	ouh->ouh_reply_size = repsize;
+
+	memcpy(ouh->ouh_inline_data, ours->ours_req, update_req_size);
+
+	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_REPLY,
+			     RCL_SERVER, repsize);
+
+	ptlrpc_request_set_replen(req);
+	req->rq_request_portal = OUT_PORTAL;
+	req->rq_reply_portal = OSC_REPLY_PORTAL;
+
+	RETURN(rc);
+}
+
+/**
+ * Prepare update request.
+ *
+ * Prepare OUT update ptlrpc request, and the request usually includes
+ * all of updates (stored in \param ureq) from one operation.
+ *
+ * \param[in] env	execution environment
+ * \param[in] imp	import on which ptlrpc request will be sent
+ * \param[in] ureq	hold all of updates which will be packed into the req
+ * \param[in] reqp	request to be created
+ *
+ * \retval		0 if preparation succeeds.
+ * \retval		negative errno if preparation fails.
+ */
+int osp_prep_update_req(const struct lu_env *env, struct obd_import *imp,
+			struct osp_update_request *our,
+			struct ptlrpc_request **reqp)
+{
+	struct ptlrpc_request		*req;
+	struct ptlrpc_bulk_desc		*desc;
+	struct osp_update_request_sub	*ours;
+	const struct object_update_request *ourq;
+	struct out_update_header	*ouh;
+	struct out_update_buffer	*oub;
+	__u32				buf_count = 0;
+	int				page_count = 0;
+	int				repsize = 0;
+	struct object_update_reply	*reply;
+	int				rc, i;
+	int				total = 0;
+	ENTRY;
+
+	list_for_each_entry(ours, &our->our_req_list, ours_list) {
+		object_update_request_dump(ours->ours_req, D_INFO);
+
+		ourq = ours->ours_req;
+		for (i = 0; i < ourq->ourq_count; i++) {
+			struct object_update	*update;
+			size_t			size = 0;
+
+
+			/* XXX: it's very inefficient to lookup update
+			 *	this way, iterating from the beginning
+			 *	each time */
+			update = object_update_request_get(ourq, i, &size);
+			LASSERT(update != NULL);
+
+			repsize += sizeof(reply->ourp_lens[0]);
+			repsize += sizeof(struct object_update_result);
+			repsize += update->ou_result_size;
+		}
+
+		buf_count++;
+	}
+	repsize += sizeof(*reply);
+	if (repsize < OUT_UPDATE_REPLY_SIZE)
+		repsize = OUT_UPDATE_REPLY_SIZE;
+	LASSERT(buf_count > 0);
+
+	req = ptlrpc_request_alloc(imp, &RQF_OUT_UPDATE);
+	if (req == NULL)
+		RETURN(-ENOMEM);
+
+	if (buf_count == 1) {
+		ours = list_entry(our->our_req_list.next,
+				  struct osp_update_request_sub, ours_list);
+
+		/* Let's check if it can be packed inline */
+		if (object_update_request_size(ours->ours_req) +
+		    sizeof(struct out_update_header) <
+				OUT_UPDATE_MAX_INLINE_SIZE) {
+			rc = osp_prep_inline_update_req(env, req, our, repsize);
+			if (rc == 0)
+				*reqp = req;
+			GOTO(out_req, rc);
+		}
+	}
+
+	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_HEADER, RCL_CLIENT,
+			     sizeof(struct osp_update_request));
+
+	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_BUF, RCL_CLIENT,
+			     buf_count * sizeof(*oub));
+
+	rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, OUT_UPDATE);
+	if (rc != 0)
+		GOTO(out_req, rc);
+
+	ouh = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE_HEADER);
+	ouh->ouh_magic = OUT_UPDATE_HEADER_MAGIC;
+	ouh->ouh_count = buf_count;
+	ouh->ouh_inline_length = 0;
+	ouh->ouh_reply_size = repsize;
+	oub = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE_BUF);
+	list_for_each_entry(ours, &our->our_req_list, ours_list) {
+		oub->oub_size = ours->ours_req_size;
+		oub++;
+		page_count += round_up(ours->ours_req_size, PAGE_SIZE) + 1;
+	}
+
+	req->rq_bulk_write = 1;
+	desc = ptlrpc_prep_bulk_imp(req, page_count,
+		MD_MAX_BRW_SIZE >> LNET_MTU_BITS,
+		PTLRPC_BULK_GET_SOURCE | PTLRPC_BULK_BUF_KIOV,
+		MDS_BULK_PORTAL, &ptlrpc_bulk_kiov_nopin_ops);
+	if (desc == NULL)
+		GOTO(out_req, rc = -ENOMEM);
+
+	/* NB req now owns desc and will free it when it gets freed */
+	list_for_each_entry(ours, &our->our_req_list, ours_list) {
+		desc->bd_frag_ops->add_iov_frag(desc, ours->ours_req,
+						ours->ours_req_size);
+		total += ours->ours_req_size;
+	}
+	CDEBUG(D_OTHER, "total %d in %u\n", total, our->our_update_nr);
+
+	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_REPLY,
+			     RCL_SERVER, repsize);
+
+	ptlrpc_request_set_replen(req);
+	req->rq_request_portal = OUT_PORTAL;
+	req->rq_reply_portal = OSC_REPLY_PORTAL;
+	*reqp = req;
+
+out_req:
+	if (rc < 0)
+		ptlrpc_req_finished(req);
+
+	RETURN(rc);
+}
+
+/**
+ * Send update RPC.
+ *
+ * Send update request to the remote MDT synchronously.
+ *
+ * \param[in] env	execution environment
+ * \param[in] imp	import on which ptlrpc request will be sent
+ * \param[in] our	hold all of updates which will be packed into the req
+ * \param[in] reqp	request to be created
+ *
+ * \retval		0 if RPC succeeds.
+ * \retval		negative errno if RPC fails.
+ */
+int osp_remote_sync(const struct lu_env *env, struct osp_device *osp,
+		    struct osp_update_request *our,
+		    struct ptlrpc_request **reqp)
+{
+	struct obd_import	*imp = osp->opd_obd->u.cli.cl_import;
+	struct ptlrpc_request	*req = NULL;
+	int			rc;
+	ENTRY;
+
+	rc = osp_prep_update_req(env, imp, our, &req);
+	if (rc != 0)
+		RETURN(rc);
+
+	osp_set_req_replay(osp, req);
+	req->rq_allow_intr = 1;
+
+	/* Note: some dt index api might return non-zero result here, like
+	 * osd_index_ea_lookup, so we should only check rc < 0 here */
+	rc = ptlrpc_queue_wait(req);
+	our->our_rc = rc;
+	if (rc < 0 || reqp == NULL)
+		ptlrpc_req_finished(req);
+	else
+		*reqp = req;
+
+	RETURN(rc);
+}
+
+/**
+ * Invalidate all objects in the osp thandle
+ *
+ * invalidate all of objects in the update request, which will be called
+ * when the transaction is aborted.
+ *
+ * \param[in] oth	osp thandle.
+ */
+static void osp_thandle_invalidate_object(const struct lu_env *env,
+					  struct osp_thandle *oth,
+					  int result)
+{
+	struct osp_update_request *our = oth->ot_our;
+	struct osp_object *obj;
+	struct osp_object *next;
+
+	if (our == NULL)
+		return;
+
+	list_for_each_entry_safe(obj, next, &our->our_invalidate_cb_list,
+				 opo_invalidate_cb_list) {
+		if (result < 0)
+			osp_invalidate(env, &obj->opo_obj);
+
+		spin_lock(&obj->opo_lock);
+		list_del_init(&obj->opo_invalidate_cb_list);
+		spin_unlock(&obj->opo_lock);
+
+		dt_object_put(env, &obj->opo_obj);
+	}
+}
+
+static void osp_trans_stop_cb(const struct lu_env *env,
+			      struct osp_thandle *oth, int result)
 {
 	struct dt_txn_commit_cb	*dcb;
 	struct dt_txn_commit_cb	*tmp;
@@ -203,6 +541,8 @@ static void osp_trans_stop_cb(struct osp_thandle *oth, int result)
 		list_del_init(&dcb->dcb_linkage);
 		dcb->dcb_func(NULL, &oth->ot_super, dcb, result);
 	}
+
+	osp_thandle_invalidate_object(env, oth, result);
 }
 
 /**
@@ -264,23 +604,34 @@ static void osp_update_callback_fini(const struct lu_env *env,
  * \retval		negative error number on failure
  */
 static int osp_update_interpret(const struct lu_env *env,
-				struct ptlrpc_request *req, void *arg, int rc)
+				struct ptlrpc_request *req, void *args, int rc)
 {
-	struct object_update_reply	*reply	= NULL;
-	struct osp_update_args		*oaua	= arg;
-	struct osp_update_request	*our = oaua->oaua_update;
-	struct osp_thandle		*oth;
-	struct osp_update_callback	*ouc;
-	struct osp_update_callback	*next;
-	int				 count	= 0;
-	int				 index  = 0;
-	int				 rc1	= 0;
+	struct object_update_reply *reply = NULL;
+	struct osp_update_args *oaua = args;
+	struct osp_update_request *our = oaua->oaua_update;
+	struct osp_thandle *oth;
+	struct osp_update_callback *ouc;
+	struct osp_update_callback *next;
+	int count = 0;
+	int index = 0;
+	int rc1 = 0;
 
 	ENTRY;
 
 	if (our == NULL)
 		RETURN(0);
 
+	/* Sigh env might be NULL in some cases, see
+	 * this calling path.
+	 * osp_send_update_thread()
+	 *  ptlrpc_set_wait() ----> null env.
+	 *   ptlrpc_check_set()
+	 *    osp_update_interpret()
+	 * Let's use env in oaua for this case.
+	 */
+	if (env == NULL)
+		env = oaua->oaua_update_env;
+
 	oaua->oaua_update = NULL;
 	oth = our->our_th;
 	if (oaua->oaua_flow_control) {
@@ -292,16 +643,16 @@ static int osp_update_interpret(const struct lu_env *env,
 	}
 
 	/* Unpack the results from the reply message. */
-	if (req->rq_repmsg != NULL) {
+	if (req->rq_repmsg != NULL && req->rq_replied) {
 		reply = req_capsule_server_sized_get(&req->rq_pill,
 						     &RMF_OUT_UPDATE_REPLY,
 						     OUT_UPDATE_REPLY_SIZE);
-		if (reply == NULL || reply->ourp_magic != UPDATE_REPLY_MAGIC)
-			rc1 = -EPROTO;
-		else
+		if (reply == NULL || reply->ourp_magic != UPDATE_REPLY_MAGIC) {
+			if (rc == 0)
+				rc = -EPROTO;
+		} else {
 			count = reply->ourp_count;
-	} else {
-		rc1 = rc;
+		}
 	}
 
 	list_for_each_entry_safe(ouc, next, &our->our_cb_items, ouc_list) {
@@ -310,18 +661,21 @@ static int osp_update_interpret(const struct lu_env *env,
 		/* The peer may only have handled some requests (indicated
 		 * by the 'count') in the packaged OUT RPC, we can only get
 		 * results for the handled part. */
-		if (index < count && reply->ourp_lens[index] > 0) {
+		if (index < count && reply->ourp_lens[index] > 0 && rc >= 0) {
 			struct object_update_result *result;
 
 			result = object_update_result_get(reply, index, NULL);
 			if (result == NULL)
-				rc1 = -EPROTO;
+				rc1 = rc = -EPROTO;
 			else
-				rc1 = result->our_rc;
-		} else {
-			rc1 = rc;
-			if (unlikely(rc1 == 0))
+				rc1 = rc = result->our_rc;
+		} else if (rc1 >= 0) {
+			/* The peer did not handle these request, let's return
+			 * -EINVAL to update interpret for now */
+			if (rc >= 0)
 				rc1 = -EINVAL;
+			else
+				rc1 = rc;
 		}
 
 		if (ouc->ouc_interpreter != NULL)
@@ -338,13 +692,13 @@ static int osp_update_interpret(const struct lu_env *env,
 	if (oth != NULL) {
 		/* oth and osp_update_requests will be destoryed in
 		 * osp_thandle_put */
-		osp_trans_stop_cb(oth, rc);
-		osp_thandle_put(oth);
+		osp_trans_stop_cb(env, oth, rc);
+		osp_thandle_put(env, oth);
 	} else {
-		osp_update_request_destroy(our);
+		osp_update_request_destroy(env, our);
 	}
 
-	RETURN(0);
+	RETURN(rc);
 }
 
 /**
@@ -367,7 +721,7 @@ int osp_unplug_async_request(const struct lu_env *env,
 	int			 rc;
 
 	rc = osp_prep_update_req(env, osp->opd_obd->u.cli.cl_import,
-				 our->our_req, &req);
+				 our, &req);
 	if (rc != 0) {
 		struct osp_update_callback *ouc;
 		struct osp_update_callback *next;
@@ -381,15 +735,19 @@ int osp_unplug_async_request(const struct lu_env *env,
 						     ouc->ouc_data, 0, rc);
 			osp_update_callback_fini(env, ouc);
 		}
-		osp_update_request_destroy(our);
+		osp_update_request_destroy(env, our);
 	} else {
-		args = ptlrpc_req_async_args(req);
+		args = ptlrpc_req_async_args(args, req);
 		args->oaua_update = our;
 		args->oaua_count = NULL;
 		args->oaua_waitq = NULL;
+		/* Note: this is asynchronous call for the request, so the
+		 * interrupte cb and current function will be different
+		 * thread, so we need use different env */
+		args->oaua_update_env = NULL;
 		args->oaua_flow_control = false;
 		req->rq_interpret_reply = osp_update_interpret;
-		ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
+		ptlrpcd_add_req(req);
 	}
 
 	return rc;
@@ -474,6 +832,7 @@ int osp_insert_update_callback(const struct lu_env *env,
  * \param[in] lens		buffer length array for the subsequent \a bufs
  * \param[in] bufs		the buffers to compose the request
  * \param[in] data		pointer to the data used by the interpreter
+ * \param[in] repsize		how many bytes the caller allocated for \a data
  * \param[in] interpreter	pointer to the interpreter function
  *
  * \retval			0 for success
@@ -481,7 +840,8 @@ int osp_insert_update_callback(const struct lu_env *env,
  */
 int osp_insert_async_request(const struct lu_env *env, enum update_type op,
 			     struct osp_object *obj, int count,
-			     __u16 *lens, const void **bufs, void *data,
+			     __u16 *lens, const void **bufs,
+			     void *data, __u32 repsize,
 			     osp_update_interpreter_t interpreter)
 {
 	struct osp_device		*osp;
@@ -489,6 +849,7 @@ int osp_insert_async_request(const struct lu_env *env, enum update_type op,
 	struct object_update		*object_update;
 	size_t				max_update_size;
 	struct object_update_request	*ureq;
+	struct osp_update_request_sub	*ours;
 	int				rc = 0;
 	ENTRY;
 
@@ -498,12 +859,16 @@ int osp_insert_async_request(const struct lu_env *env, enum update_type op,
 		RETURN(PTR_ERR(our));
 
 again:
-	ureq = our->our_req;
-	max_update_size = our->our_req_size - object_update_request_size(ureq);
+	ours = osp_current_object_update_request(our);
+
+	ureq = ours->ours_req;
+	max_update_size = ours->ours_req_size -
+			  object_update_request_size(ureq);
 
 	object_update = update_buffer_get_update(ureq, ureq->ourq_count);
-	rc = out_update_pack(env, object_update, max_update_size, op,
-			     lu_object_fid(osp2lu_obj(obj)), count, lens, bufs);
+	rc = out_update_pack(env, object_update, &max_update_size, op,
+			     lu_object_fid(osp2lu_obj(obj)), count, lens, bufs,
+			     repsize);
 	/* The queue is full. */
 	if (rc == -E2BIG) {
 		osp->opd_async_requests = NULL;
@@ -524,6 +889,7 @@ again:
 			RETURN(rc);
 
 		ureq->ourq_count++;
+		our->our_update_nr++;
 	}
 
 	rc = osp_insert_update_callback(env, our, obj, data, interpreter);
@@ -545,21 +911,20 @@ int osp_trans_update_request_create(struct thandle *th)
 		return PTR_ERR(our);
 	}
 
-	if (dt2osp_dev(th->th_dev)->opd_connect_mdt)
-		our->our_flags = UPDATE_FL_SYNC;
-
 	oth->ot_our = our;
 	our->our_th = oth;
+
 	return 0;
 }
 
-void osp_thandle_destroy(struct osp_thandle *oth)
+void osp_thandle_destroy(const struct lu_env *env,
+			 struct osp_thandle *oth)
 {
 	LASSERT(oth->ot_magic == OSP_THANDLE_MAGIC);
 	LASSERT(list_empty(&oth->ot_commit_dcb_list));
 	LASSERT(list_empty(&oth->ot_stop_dcb_list));
 	if (oth->ot_our != NULL)
-		osp_update_request_destroy(oth->ot_our);
+		osp_update_request_destroy(env, oth->ot_our);
 	OBD_FREE_PTR(oth);
 }
 
@@ -603,7 +968,6 @@ struct thandle *osp_trans_create(const struct lu_env *env, struct dt_device *d)
 	oth->ot_magic = OSP_THANDLE_MAGIC;
 	th = &oth->ot_super;
 	th->th_dev = d;
-	th->th_tags = LCT_TX_HANDLE;
 
 	atomic_set(&oth->ot_refcount, 1);
 	INIT_LIST_HEAD(&oth->ot_commit_dcb_list);
@@ -613,112 +977,6 @@ struct thandle *osp_trans_create(const struct lu_env *env, struct dt_device *d)
 }
 
 /**
- * Prepare update request.
- *
- * Prepare OUT update ptlrpc request, and the request usually includes
- * all of updates (stored in \param ureq) from one operation.
- *
- * \param[in] env	execution environment
- * \param[in] imp	import on which ptlrpc request will be sent
- * \param[in] ureq	hold all of updates which will be packed into the req
- * \param[in] reqp	request to be created
- *
- * \retval		0 if preparation succeeds.
- * \retval		negative errno if preparation fails.
- */
-int osp_prep_update_req(const struct lu_env *env, struct obd_import *imp,
-			const struct object_update_request *ureq,
-			struct ptlrpc_request **reqp)
-{
-	struct ptlrpc_request		*req;
-	struct object_update_request	*tmp;
-	size_t				ureq_len;
-	int				rc;
-	ENTRY;
-
-	object_update_request_dump(ureq, D_INFO);
-	req = ptlrpc_request_alloc(imp, &RQF_OUT_UPDATE);
-	if (req == NULL)
-		RETURN(-ENOMEM);
-
-	ureq_len = object_update_request_size(ureq);
-	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE, RCL_CLIENT,
-			     ureq_len);
-
-	rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, OUT_UPDATE);
-	if (rc != 0) {
-		ptlrpc_req_finished(req);
-		RETURN(rc);
-	}
-
-	req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_REPLY,
-			     RCL_SERVER, OUT_UPDATE_REPLY_SIZE);
-
-	tmp = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE);
-	memcpy(tmp, ureq, ureq_len);
-
-	ptlrpc_request_set_replen(req);
-	req->rq_request_portal = OUT_PORTAL;
-	req->rq_reply_portal = OSC_REPLY_PORTAL;
-	*reqp = req;
-
-	RETURN(rc);
-}
-
-/**
- * Send update RPC.
- *
- * Send update request to the remote MDT synchronously.
- *
- * \param[in] env	execution environment
- * \param[in] imp	import on which ptlrpc request will be sent
- * \param[in] our	hold all of updates which will be packed into the req
- * \param[in] reqp	request to be created
- *
- * \retval		0 if RPC succeeds.
- * \retval		negative errno if RPC fails.
- */
-
-int osp_remote_sync(const struct lu_env *env, struct osp_device *osp,
-		    struct osp_update_request *our,
-		    struct ptlrpc_request **reqp)
-{
-	struct obd_import	*imp = osp->opd_obd->u.cli.cl_import;
-	struct ptlrpc_request	*req = NULL;
-	int			rc;
-	ENTRY;
-
-	rc = osp_prep_update_req(env, imp, our->our_req, &req);
-	if (rc != 0)
-		RETURN(rc);
-
-	/* This will only be called with read-only update, and these updates
-	 * might be used to retrieve update log during recovery process, so
-	 * it will be allowed to send during recovery process */
-	req->rq_allow_replay = 1;
-
-	/* Note: some dt index api might return non-zero result here, like
-	 * osd_index_ea_lookup, so we should only check rc < 0 here */
-	rc = ptlrpc_queue_wait(req);
-	if (rc < 0) {
-		ptlrpc_req_finished(req);
-		our->our_rc = rc;
-		RETURN(rc);
-	}
-
-	if (reqp != NULL) {
-		*reqp = req;
-		RETURN(rc);
-	}
-
-	our->our_rc = rc;
-
-	ptlrpc_req_finished(req);
-
-	RETURN(rc);
-}
-
-/**
  * Add commit callback to transaction.
  *
  * Add commit callback to the osp thandle, which will be called
@@ -771,7 +1029,8 @@ static void osp_request_commit_cb(struct ptlrpc_request *req)
 		RETURN_EXIT;
 
 	oth = thandle_to_osp_thandle(th);
-	if (lustre_msg_get_last_committed(req->rq_repmsg))
+	if (req->rq_repmsg != NULL &&
+	    lustre_msg_get_last_committed(req->rq_repmsg))
 		last_committed_transno =
 			lustre_msg_get_last_committed(req->rq_repmsg);
 
@@ -780,7 +1039,7 @@ static void osp_request_commit_cb(struct ptlrpc_request *req)
 		last_committed_transno =
 			req->rq_import->imp_peer_committed_transno;
 
-	CDEBUG(D_HA, "trans no "LPU64" committed transno "LPU64"\n",
+	CDEBUG(D_HA, "trans no %llu committed transno %llu\n",
 	       req->rq_transno, last_committed_transno);
 
 	/* If the transaction is not really committed, mark result = 1 */
@@ -790,7 +1049,7 @@ static void osp_request_commit_cb(struct ptlrpc_request *req)
 
 	osp_trans_commit_cb(oth, result);
 	req->rq_committed = 1;
-	osp_thandle_put(oth);
+	osp_thandle_put(NULL, oth);
 	EXIT;
 }
 
@@ -823,7 +1082,7 @@ void osp_trans_callback(const struct lu_env *env,
 			osp_update_callback_fini(env, ouc);
 		}
 	}
-	osp_trans_stop_cb(oth, rc);
+	osp_trans_stop_cb(env, oth, rc);
 	osp_trans_commit_cb(oth, rc);
 }
 
@@ -849,35 +1108,36 @@ static int osp_send_update_req(const struct lu_env *env,
 {
 	struct osp_update_args	*args;
 	struct ptlrpc_request	*req;
-	struct lu_device *top_device;
 	struct osp_thandle	*oth = our->our_th;
 	int	rc = 0;
 	ENTRY;
 
 	LASSERT(oth != NULL);
-	LASSERT(our->our_req_sent == 0);
 	rc = osp_prep_update_req(env, osp->opd_obd->u.cli.cl_import,
-				 our->our_req, &req);
+				 our, &req);
 	if (rc != 0) {
 		osp_trans_callback(env, oth, rc);
 		RETURN(rc);
 	}
 
-	args = ptlrpc_req_async_args(req);
+	args = ptlrpc_req_async_args(args, req);
 	args->oaua_update = our;
+	/* set env to NULL, in case the interrupt cb and current function
+	 * are in different thread */
+	args->oaua_update_env = NULL;
 	osp_thandle_get(oth); /* hold for update interpret */
 	req->rq_interpret_reply = osp_update_interpret;
 	if (!oth->ot_super.th_wait_submit && !oth->ot_super.th_sync) {
 		if (!osp->opd_imp_active || !osp->opd_imp_connected) {
 			osp_trans_callback(env, oth, rc);
-			osp_thandle_put(oth);
+			osp_thandle_put(env, oth);
 			GOTO(out, rc = -ENOTCONN);
 		}
 
 		rc = obd_get_request_slot(&osp->opd_obd->u.cli);
 		if (rc != 0) {
 			osp_trans_callback(env, oth, rc);
-			osp_thandle_put(oth);
+			osp_thandle_put(env, oth);
 			GOTO(out, rc = -ENOTCONN);
 		}
 		args->oaua_flow_control = true;
@@ -885,12 +1145,12 @@ static int osp_send_update_req(const struct lu_env *env,
 		if (!osp->opd_connect_mdt) {
 			down_read(&osp->opd_async_updates_rwsem);
 			args->oaua_count = &osp->opd_async_updates_count;
-			args->oaua_waitq = &osp->opd_syn_barrier_waitq;
+			args->oaua_waitq = &osp->opd_sync_barrier_waitq;
 			up_read(&osp->opd_async_updates_rwsem);
 			atomic_inc(args->oaua_count);
 		}
 
-		ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
+		ptlrpcd_add_req(req);
 		req = NULL;
 	} else {
 		osp_thandle_get(oth); /* hold for commit callback */
@@ -904,26 +1164,33 @@ static int osp_send_update_req(const struct lu_env *env,
 		 * status, in case the other target is being recoveried
 		 * at the same time, and if we wait here for the import
 		 * to be recoveryed, it might cause deadlock */
-		top_device = osp->opd_dt_dev.dd_lu_dev.ld_site->ls_top_dev;
-		if (top_device->ld_obd->obd_recovering)
-			req->rq_allow_replay = 1;
-
-		osp_get_rpc_lock(osp);
+		osp_set_req_replay(osp, req);
+
+		/* Because this req will be synchronus, i.e. it will be called
+		 * in the same thread, so it will be safe to use current
+		 * env */
+		args->oaua_update_env = env;
+		if (osp->opd_connect_mdt)
+			osp_get_rpc_lock(osp);
 		rc = ptlrpc_queue_wait(req);
-		osp_put_rpc_lock(osp);
-		if ((rc == -ENOMEM && req->rq_set == NULL) ||
+		if (osp->opd_connect_mdt)
+			osp_put_rpc_lock(osp);
+
+		/* We use rq_queued_time to distinguish between local
+		 * and remote -ENOMEM. */
+		if ((rc == -ENOMEM && req->rq_queued_time == 0) ||
 		    (req->rq_transno == 0 && !req->rq_committed)) {
 			if (args->oaua_update != NULL) {
 				/* If osp_update_interpret is not being called,
 				 * release the osp_thandle */
 				args->oaua_update = NULL;
-				osp_thandle_put(oth);
+				osp_thandle_put(env, oth);
 			}
 
 			req->rq_cb_data = NULL;
 			rc = rc == 0 ? req->rq_status : rc;
 			osp_trans_callback(env, oth, rc);
-			osp_thandle_put(oth);
+			osp_thandle_put(env, oth);
 			GOTO(out, rc);
 		}
 	}
@@ -938,7 +1205,7 @@ out:
  * Get local thandle for osp_thandle
  *
  * Get the local OSD thandle from the OSP thandle. Currently, there
- * are a few OSP API (osp_object_create() and osp_sync_add()) needs
+ * are a few OSP API (osp_create() and osp_sync_add()) needs
  * to update the object on local OSD device.
  *
  * If the osp_thandle comes from normal stack (MDD->LOD->OSP), then
@@ -986,16 +1253,17 @@ struct thandle *osp_get_storage_thandle(const struct lu_env *env,
 /**
  * Set version for the transaction
  *
- * Set the version for the transaction, then the osp RPC will be
- * sent in the order of version, i.e. the transaction with lower
- * version will be sent first.
+ * Set the version for the transaction and add the request to
+ * the sending list, then after transaction stop, the request
+ * will be sent in the order of version by the sending thread.
  *
  * \param [in] oth	osp thandle to be set version.
  *
  * \retval		0 if set version succeeds
  *                      negative errno if set version fails.
  */
-int osp_check_and_set_rpc_version(struct osp_thandle *oth)
+int osp_check_and_set_rpc_version(struct osp_thandle *oth,
+				  struct osp_object *obj)
 {
 	struct osp_device *osp = dt2osp_dev(oth->ot_super.th_dev);
 	struct osp_updates *ou = osp->opd_update;
@@ -1003,15 +1271,31 @@ int osp_check_and_set_rpc_version(struct osp_thandle *oth)
 	if (ou == NULL)
 		return -EIO;
 
-	if (oth->ot_version != 0)
+	if (oth->ot_our->our_version != 0)
 		return 0;
 
 	spin_lock(&ou->ou_lock);
-	oth->ot_version = ou->ou_version++;
+	spin_lock(&oth->ot_our->our_list_lock);
+	if (obj->opo_stale) {
+		spin_unlock(&oth->ot_our->our_list_lock);
+		spin_unlock(&ou->ou_lock);
+		return -ESTALE;
+	}
+
+	/* Assign the version and add it to the sending list */
+	osp_thandle_get(oth);
+	oth->ot_our->our_version = ou->ou_version++;
+	oth->ot_our->our_generation = ou->ou_generation;
+	list_add_tail(&oth->ot_our->our_list,
+		      &osp->opd_update->ou_list);
+	oth->ot_our->our_req_ready = 0;
+	spin_unlock(&oth->ot_our->our_list_lock);
 	spin_unlock(&ou->ou_lock);
 
-	CDEBUG(D_INFO, "%s: version "LPU64" oth:version %p:"LPU64"\n",
-	       osp->opd_obd->obd_name, ou->ou_version, oth, oth->ot_version);
+	LASSERT(oth->ot_super.th_wait_submit == 1);
+	CDEBUG(D_INFO, "%s: version %llu gen %llu oth:version %p:%llu\n",
+	       osp->opd_obd->obd_name, ou->ou_version, ou->ou_generation, oth,
+	       oth->ot_our->our_version);
 
 	return 0;
 }
@@ -1039,38 +1323,96 @@ osp_get_next_request(struct osp_updates *ou, struct osp_update_request **ourp)
 	spin_lock(&ou->ou_lock);
 	list_for_each_entry_safe(our, tmp, &ou->ou_list, our_list) {
 		LASSERT(our->our_th != NULL);
-		CDEBUG(D_INFO, "our %p version "LPU64" rpc_version "LPU64"\n",
-		       our, our->our_th->ot_version, ou->ou_rpc_version);
-		if (our->our_th->ot_version == 0) {
-			list_del_init(&our->our_list);
-			*ourp = our;
-			got_req = true;
-			break;
-		}
-
+		CDEBUG(D_HA, "ou %p version %llu rpc_version %llu\n",
+		       ou, our->our_version, ou->ou_rpc_version);
+		spin_lock(&our->our_list_lock);
 		/* Find next osp_update_request in the list */
-		if (our->our_th->ot_version == ou->ou_rpc_version) {
+		if (our->our_version == ou->ou_rpc_version &&
+		    our->our_req_ready) {
 			list_del_init(&our->our_list);
+			spin_unlock(&our->our_list_lock);
 			*ourp = our;
 			got_req = true;
 			break;
 		}
+		spin_unlock(&our->our_list_lock);
 	}
 	spin_unlock(&ou->ou_lock);
 
 	return got_req;
 }
 
-static void osp_update_rpc_version(struct osp_updates *ou,
-				   struct osp_thandle *oth)
+/**
+ * Invalidate update request
+ *
+ * Invalidate update request in the OSP sending list, so all of
+ * requests in the sending list will return error, which happens
+ * when it finds one update (with writing llog) requests fails or
+ * the OSP is evicted by remote target. see osp_send_update_thread().
+ *
+ * \param[in] osp	OSP device whose update requests will be
+ *                      invalidated.
+ **/
+void osp_invalidate_request(struct osp_device *osp)
 {
-	if (oth->ot_version == 0)
+	struct lu_env env;
+	struct osp_updates *ou = osp->opd_update;
+	struct osp_update_request *our;
+	struct osp_update_request *tmp;
+	LIST_HEAD(list);
+	int			rc;
+	ENTRY;
+
+	if (ou == NULL)
 		return;
 
-	LASSERT(oth->ot_version == ou->ou_rpc_version);
+	rc = lu_env_init(&env, osp->opd_dt_dev.dd_lu_dev.ld_type->ldt_ctx_tags);
+	if (rc < 0) {
+		CERROR("%s: init env error: rc = %d\n", osp->opd_obd->obd_name,
+		       rc);
+
+		spin_lock(&ou->ou_lock);
+		ou->ou_generation++;
+		spin_unlock(&ou->ou_lock);
+
+		return;
+	}
+
 	spin_lock(&ou->ou_lock);
-	ou->ou_rpc_version++;
+	/* invalidate all of request in the sending list */
+	list_for_each_entry_safe(our, tmp, &ou->ou_list, our_list) {
+		spin_lock(&our->our_list_lock);
+		if (our->our_req_ready)
+			list_move(&our->our_list, &list);
+		else
+			list_del_init(&our->our_list);
+
+		if (our->our_th->ot_super.th_result == 0)
+			our->our_th->ot_super.th_result = -EIO;
+
+		if (our->our_version >= ou->ou_rpc_version)
+			ou->ou_rpc_version = our->our_version + 1;
+		spin_unlock(&our->our_list_lock);
+
+		CDEBUG(D_HA, "%s invalidate our %p\n", osp->opd_obd->obd_name,
+		       our);
+	}
+
+	/* Increase the generation, then the update request with old generation
+	 * will fail with -EIO. */
+	ou->ou_generation++;
 	spin_unlock(&ou->ou_lock);
+
+	/* invalidate all of request in the sending list */
+	list_for_each_entry_safe(our, tmp, &list, our_list) {
+		spin_lock(&our->our_list_lock);
+		list_del_init(&our->our_list);
+		spin_unlock(&our->our_list_lock);
+		osp_trans_callback(&env, our->our_th,
+				   our->our_th->ot_super.th_result);
+		osp_thandle_put(&env, our->our_th);
+	}
+	lu_env_fini(&env);
 }
 
 /**
@@ -1090,7 +1432,6 @@ int osp_send_update_thread(void *arg)
 {
 	struct lu_env		env;
 	struct osp_device	*osp = arg;
-	struct l_wait_info	 lwi = { 0 };
 	struct osp_updates	*ou = osp->opd_update;
 	struct ptlrpc_thread	*thread = &osp->opd_update_thread;
 	struct osp_update_request *our = NULL;
@@ -1109,34 +1450,46 @@ int osp_send_update_thread(void *arg)
 	wake_up(&thread->t_ctl_waitq);
 	while (1) {
 		our = NULL;
-		l_wait_event(ou->ou_waitq,
-			     !osp_send_update_thread_running(osp) ||
-			     osp_get_next_request(ou, &our),
-			     &lwi);
+		wait_event_idle(ou->ou_waitq,
+				!osp_send_update_thread_running(osp) ||
+				osp_get_next_request(ou, &our));
 
 		if (!osp_send_update_thread_running(osp)) {
-			if (our != NULL && our->our_th != NULL) {
+			if (our != NULL) {
 				osp_trans_callback(&env, our->our_th, -EINTR);
-				osp_thandle_put(our->our_th);
+				osp_thandle_put(&env, our->our_th);
 			}
 			break;
 		}
 
-		if (our->our_req_sent == 0) {
-			if (our->our_th != NULL &&
-			    our->our_th->ot_super.th_result != 0)
-				osp_trans_callback(&env, our->our_th,
-					our->our_th->ot_super.th_result);
-			else
-				rc = osp_send_update_req(&env, osp, our);
+		LASSERT(our->our_th != NULL);
+		if (our->our_th->ot_super.th_result != 0) {
+			osp_trans_callback(&env, our->our_th,
+				our->our_th->ot_super.th_result);
+			rc = our->our_th->ot_super.th_result;
+		} else if (ou->ou_generation != our->our_generation ||
+			   OBD_FAIL_CHECK(OBD_FAIL_INVALIDATE_UPDATE)) {
+			rc = -EIO;
+			osp_trans_callback(&env, our->our_th, rc);
+		} else {
+			rc = osp_send_update_req(&env, osp, our);
 		}
 
-		if (our->our_th != NULL) {
-			/* Update the rpc version */
-			osp_update_rpc_version(ou, our->our_th);
-			/* Balanced for thandle_get in osp_trans_trigger() */
-			osp_thandle_put(our->our_th);
-		}
+		/* Update the rpc version */
+		spin_lock(&ou->ou_lock);
+		if (our->our_version == ou->ou_rpc_version)
+			ou->ou_rpc_version++;
+		spin_unlock(&ou->ou_lock);
+
+		/* If one update request fails, let's fail all of the requests
+		 * in the sending list, because the request in the sending
+		 * list are dependent on either other, continue sending these
+		 * request might cause llog or filesystem corruption */
+		if (rc < 0)
+			osp_invalidate_request(osp);
+
+		/* Balanced for thandle_get in osp_check_and_set_rpc_version */
+		osp_thandle_put(&env, our->our_th);
 	}
 
 	thread->t_flags = SVC_STOPPED;
@@ -1147,36 +1500,6 @@ int osp_send_update_thread(void *arg)
 }
 
 /**
- * Trigger the request for remote updates.
- *
- * Add the request to the sending list, and wake up osp update
- * sending thread.
- *
- * \param[in] env		pointer to the thread context
- * \param[in] osp		pointer to the OSP device
- * \param[in] oth		pointer to the transaction handler
- *
- */
-static void osp_trans_trigger(const struct lu_env *env,
-			     struct osp_device *osp,
-			     struct osp_thandle *oth)
-{
-
-	CDEBUG(D_INFO, "%s: add oth %p with version "LPU64"\n",
-	       osp->opd_obd->obd_name, oth, oth->ot_version);
-
-	LASSERT(oth->ot_magic == OSP_THANDLE_MAGIC);
-	osp_thandle_get(oth);
-	LASSERT(oth->ot_our != NULL);
-	spin_lock(&osp->opd_update->ou_lock);
-	list_add_tail(&oth->ot_our->our_list,
-		      &osp->opd_update->ou_list);
-	spin_unlock(&osp->opd_update->ou_lock);
-
-	wake_up(&osp->opd_update->ou_waitq);
-}
-
-/**
  * The OSP layer dt_device_operations::dt_trans_start() interface
  * to start the transaction.
  *
@@ -1196,6 +1519,8 @@ int osp_trans_start(const struct lu_env *env, struct dt_device *dt,
 {
 	struct osp_thandle	*oth = thandle_to_osp_thandle(th);
 
+	if (oth->ot_super.th_sync)
+		oth->ot_our->our_flags |= UPDATE_FL_SYNC;
 	/* For remote thandle, if there are local thandle, start it here*/
 	if (is_only_remote_trans(th) && oth->ot_storage_th != NULL)
 		return dt_trans_start(env, oth->ot_storage_th->th_dev,
@@ -1208,7 +1533,7 @@ int osp_trans_start(const struct lu_env *env, struct dt_device *dt,
  * to stop the transaction.
  *
  * If the transaction is a remote transaction, related remote
- * updates will be triggered here via osp_trans_trigger().
+ * updates will be triggered at the end of this function.
  *
  * For synchronous mode update or any failed update, the request
  * will be destroyed explicitly when the osp_trans_stop().
@@ -1239,13 +1564,13 @@ int osp_trans_stop(const struct lu_env *env, struct dt_device *dt,
 		oth->ot_storage_th = NULL;
 	}
 
-	if (our == NULL || our->our_req == NULL ||
-	    our->our_req->ourq_count == 0) {
+	if (our == NULL || list_empty(&our->our_req_list)) {
 		osp_trans_callback(env, oth, th->th_result);
 		GOTO(out, rc = th->th_result);
 	}
 
 	if (!osp->opd_connect_mdt) {
+		osp_trans_callback(env, oth, th->th_result);
 		rc = osp_send_update_req(env, osp, oth->ot_our);
 		GOTO(out, rc);
 	}
@@ -1256,19 +1581,27 @@ int osp_trans_stop(const struct lu_env *env, struct dt_device *dt,
 		GOTO(out, rc = -EIO);
 	}
 
-	if (th->th_sync) {
-		/* if th_sync is set, then it needs to be sent
-		 * right away. Note: even thought the RPC has been
-		 * sent, it still needs to be added to the sending
-		 * list (see osp_trans_trigger()), so ou_rpc_version
-		 * can be updated correctly. */
+	CDEBUG(D_HA, "%s: add oth %p with version %llu\n",
+	       osp->opd_obd->obd_name, oth, our->our_version);
+
+	LASSERT(our->our_req_ready == 0);
+	spin_lock(&our->our_list_lock);
+	if (likely(!list_empty(&our->our_list))) {
+		/* notify sending thread */
+		our->our_req_ready = 1;
+		wake_up(&osp->opd_update->ou_waitq);
+		spin_unlock(&our->our_list_lock);
+	} else if (th->th_result == 0) {
+		/* if the request does not needs to be serialized,
+		 * read-only request etc, let's send it right away */
+		spin_unlock(&our->our_list_lock);
 		rc = osp_send_update_req(env, osp, our);
-		our->our_req_sent = 1;
+	} else {
+		spin_unlock(&our->our_list_lock);
+		osp_trans_callback(env, oth, th->th_result);
 	}
-
-	osp_trans_trigger(env, osp, oth);
 out:
-	osp_thandle_put(oth);
+	osp_thandle_put(env, oth);
 
 	RETURN(rc);
 }