X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fosp%2Fosp_md_object.c;h=c0314572e9493001a36cf350d5c72a095a055a8c;hp=9bed8da8840ce11ccd712ac1c817971a6edb682b;hb=26b8238659974959780cd49de92595b4b0bdf89f;hpb=e88992a3b5b9d9ba0a69883671f1b5888514e05d

diff --git a/lustre/osp/osp_md_object.c b/lustre/osp/osp_md_object.c
index 9bed8da..c031457 100644
--- a/lustre/osp/osp_md_object.c
+++ b/lustre/osp/osp_md_object.c
@@ -20,12 +20,33 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2013, Intel Corporation.
+ * Copyright (c) 2013, 2014, Intel Corporation.
  */
 /*
  * lustre/osp/osp_md_object.c
  *
- * Lustre MDT Proxy Device
+ * OST/MDT proxy device (OSP) Metadata methods
+ *
+ * This file implements methods for remote MD object, which include
+ * dt_object_operations, dt_index_operations and dt_body_operations.
+ *
+ * If there are multiple MDTs in one filesystem, one operation might
+ * include modifications in several MDTs. In such cases, clients
+ * send the RPC to the master MDT, then the operation is decomposed into
+ * object updates which will be dispatched to OSD or OSP. The local updates
+ * go to local OSD and the remote updates go to OSP. In OSP, these remote
+ * object updates will be packed into an update RPC, sent to the remote MDT
+ * and handled by Object Update Target (OUT).
+ *
+ * In DNE phase I, because of missing complete recovery solution, updates
+ * will be executed in order and synchronously.
+ *     1. The transaction is created.
+ *     2. In transaction declare, it collects and packs remote
+ *        updates (in osp_md_declare_xxx()).
+ *     3. In transaction start, it sends these remote updates
+ *        to remote MDTs, which will execute these updates synchronously.
+ *     4. In transaction execute phase, the local updates will be executed
+ *        synchronously.
  *
  * Author: Di Wang <di.wang@intel.com>
  */
@@ -38,22 +59,33 @@
 static const char dot[] = ".";
 static const char dotdot[] = "..";
 
-int osp_md_declare_object_create(const struct lu_env *env,
-				 struct dt_object *dt,
-				 struct lu_attr *attr,
-				 struct dt_allocation_hint *hint,
-				 struct dt_object_format *dof,
-				 struct thandle *th)
+/**
+ * Add OUT_CREATE sub-request into the OUT RPC.
+ *
+ * Note: if the object has already been created, we must add object
+ * destroy sub-request ahead of the create, so it will destroy then
+ * re-create the object.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be created
+ * \param[in] attr	attribute of the created object
+ * \param[in] hint	creation hint
+ * \param[in] dof	creation format information
+ * \param[in] th	the transaction handle
+ *
+ * \retval		only return 0 for now
+ */
+static int __osp_md_declare_object_create(const struct lu_env *env,
+					  struct dt_object *dt,
+					  struct lu_attr *attr,
+					  struct dt_allocation_hint *hint,
+					  struct dt_object_format *dof,
+					  struct thandle *th)
 {
-	struct osp_thread_info		*osi = osp_env_info(env);
 	struct dt_update_request	*update;
-	struct lu_fid			*fid1;
-	int				sizes[2] = {sizeof(struct obdo), 0};
-	char				*bufs[2] = {NULL, NULL};
-	int				buf_count;
 	int				rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: rc = %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -61,25 +93,6 @@ int osp_md_declare_object_create(const struct lu_env *env,
 		return PTR_ERR(update);
 	}
 
-	osi->osi_obdo.o_valid = 0;
-	obdo_from_la(&osi->osi_obdo, attr, attr->la_valid);
-	lustre_set_wire_obdo(NULL, &osi->osi_obdo, &osi->osi_obdo);
-	obdo_cpu_to_le(&osi->osi_obdo, &osi->osi_obdo);
-
-	bufs[0] = (char *)&osi->osi_obdo;
-	buf_count = 1;
-	fid1 = (struct lu_fid *)lu_object_fid(&dt->do_lu);
-	if (hint != NULL && hint->dah_parent) {
-		struct lu_fid *fid2;
-		struct lu_fid *tmp_fid = &osi->osi_fid;
-
-		fid2 = (struct lu_fid *)lu_object_fid(&hint->dah_parent->do_lu);
-		fid_cpu_to_le(tmp_fid, fid2);
-		sizes[1] = sizeof(*tmp_fid);
-		bufs[1] = (char *)tmp_fid;
-		buf_count++;
-	}
-
 	if (lu_object_exists(&dt->do_lu)) {
 		/* If the object already exists, we needs to destroy
 		 * this orphan object first.
@@ -95,23 +108,27 @@ int osp_md_declare_object_create(const struct lu_env *env,
 		 *    but find the object already exists
 		 */
 		CDEBUG(D_HA, "%s: object "DFID" exists, destroy this orphan\n",
-		       dt->do_lu.lo_dev->ld_obd->obd_name, PFID(fid1));
+		       dt->do_lu.lo_dev->ld_obd->obd_name,
+		       PFID(lu_object_fid(&dt->do_lu)));
 
-		rc = out_insert_update(env, update, OUT_REF_DEL, fid1, 0,
-				       NULL, NULL);
+		rc = out_ref_del_pack(env, &update->dur_buf,
+				      lu_object_fid(&dt->do_lu),
+				      update->dur_batchid);
 		if (rc != 0)
 			GOTO(out, rc);
 
 		if (S_ISDIR(lu_object_attr(&dt->do_lu))) {
 			/* decrease for ".." */
-			rc = out_insert_update(env, update, OUT_REF_DEL, fid1,
-					       0, NULL, NULL);
+			rc = out_ref_del_pack(env, &update->dur_buf,
+					      lu_object_fid(&dt->do_lu),
+					      update->dur_batchid);
 			if (rc != 0)
 				GOTO(out, rc);
 		}
 
-		rc = out_insert_update(env, update, OUT_DESTROY, fid1, 0, NULL,
-				       NULL);
+		rc = out_object_destroy_pack(env, &update->dur_buf,
+					     lu_object_fid(&dt->do_lu),
+					     update->dur_batchid);
 		if (rc != 0)
 			GOTO(out, rc);
 
@@ -121,8 +138,11 @@ int osp_md_declare_object_create(const struct lu_env *env,
 		update_inc_batchid(update);
 	}
 
-	rc = out_insert_update(env, update, OUT_CREATE, fid1, buf_count, sizes,
-			       (const char **)bufs);
+	rc = out_create_pack(env, &update->dur_buf,
+			     lu_object_fid(&dt->do_lu), attr, hint, dof,
+			     update->dur_batchid);
+	if (rc != 0)
+		GOTO(out, rc);
 out:
 	if (rc)
 		CERROR("%s: Insert update error: rc = %d\n",
@@ -131,33 +151,101 @@ out:
 	return rc;
 }
 
+/**
+ * Implementation of dt_object_operations::do_declare_create
+ *
+ * For non-remote transaction, it will add an OUT_CREATE sub-request
+ * into the OUT RPC that will be flushed when the transaction start.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	remote object to be created
+ * \param[in] attr	attribute of the created object
+ * \param[in] hint	creation hint
+ * \param[in] dof	creation format information
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+int osp_md_declare_object_create(const struct lu_env *env,
+				 struct dt_object *dt,
+				 struct lu_attr *attr,
+				 struct dt_allocation_hint *hint,
+				 struct dt_object_format *dof,
+				 struct thandle *th)
+{
+	int rc = 0;
+
+	if (!is_only_remote_trans(th)) {
+		rc = __osp_md_declare_object_create(env, dt, attr, hint,
+						    dof, th);
+
+		CDEBUG(D_INFO, "declare create md_object "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
+
+	return rc;
+}
+
+/**
+ * Implementation of dt_object_operations::do_create
+ *
+ * For remote transaction, it will add an OUT_CREATE sub-request into
+ * the OUT RPC that will be flushed when the transaction stop.
+ *
+ * It sets necessary flags for created object. In DNE phase I,
+ * remote updates are actually executed during transaction start,
+ * i.e. the object has already been created when calling this method.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be created
+ * \param[in] attr	attribute of the created object
+ * \param[in] hint	creation hint
+ * \param[in] dof	creation format information
+ * \param[in] th	the transaction handle
+ *
+ * \retval		only return 0 for now
+ */
 int osp_md_object_create(const struct lu_env *env, struct dt_object *dt,
 			 struct lu_attr *attr, struct dt_allocation_hint *hint,
 			 struct dt_object_format *dof, struct thandle *th)
 {
-	struct osp_object  *obj = dt2osp_obj(dt);
+	int rc = 0;
 
-	CDEBUG(D_INFO, "create object "DFID"\n",
-	       PFID(&dt->do_lu.lo_header->loh_fid));
+	if (is_only_remote_trans(th)) {
+		rc = __osp_md_declare_object_create(env, dt, attr, hint,
+						    dof, th);
 
-	/* Because the create update RPC will be sent during declare phase,
-	 * if creation reaches here, it means the object has been created
-	 * successfully */
-	dt->do_lu.lo_header->loh_attr |= LOHA_EXISTS | (attr->la_mode & S_IFMT);
-	obj->opo_empty = 1;
+		CDEBUG(D_INFO, "create md_object "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
 
-	return 0;
+	if (rc == 0) {
+		dt->do_lu.lo_header->loh_attr |= LOHA_EXISTS |
+						 (attr->la_mode & S_IFMT);
+		dt2osp_obj(dt)->opo_non_exist = 0;
+	}
+
+	return rc;
 }
 
-static int osp_md_declare_object_ref_del(const struct lu_env *env,
-					 struct dt_object *dt,
-					 struct thandle *th)
+/**
+ * Add OUT_REF_DEL sub-request into the OUT RPC.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to decrease the reference count.
+ * \param[in] th	the transaction handle of refcount decrease.
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int __osp_md_ref_del(const struct lu_env *env, struct dt_object *dt,
+			    struct thandle *th)
 {
 	struct dt_update_request	*update;
-	struct lu_fid			*fid;
 	int				rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: rc = %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -165,31 +253,84 @@ static int osp_md_declare_object_ref_del(const struct lu_env *env,
 		return PTR_ERR(update);
 	}
 
-	fid = (struct lu_fid *)lu_object_fid(&dt->do_lu);
+	rc = out_ref_del_pack(env, &update->dur_buf,
+			      lu_object_fid(&dt->do_lu),
+			      update->dur_batchid);
+	return rc;
+}
 
-	rc = out_insert_update(env, update, OUT_REF_DEL, fid, 0, NULL, NULL);
+/**
+ * Implementation of dt_object_operations::do_declare_ref_del
+ *
+ * For non-remote transaction, it will add an OUT_REF_DEL sub-request
+ * into the OUT RPC that will be flushed when the transaction start.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to decrease the reference count.
+ * \param[in] th	the transaction handle of refcount decrease.
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int osp_md_declare_ref_del(const struct lu_env *env,
+				  struct dt_object *dt, struct thandle *th)
+{
+	int rc = 0;
+
+	if (!is_only_remote_trans(th)) {
+		rc = __osp_md_ref_del(env, dt, th);
+
+		CDEBUG(D_INFO, "declare ref del "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
 
 	return rc;
 }
 
-static int osp_md_object_ref_del(const struct lu_env *env,
-				 struct dt_object *dt,
-				 struct thandle *th)
+/**
+ * Implementation of dt_object_operations::do_ref_del
+ *
+ * For remote transaction, it will add an OUT_REF_DEL sub-request into
+ * the OUT RPC that will be flushed when the transaction stop.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to decrease the reference count
+ * \param[in] th	the transaction handle
+ *
+ * \retval		only return 0 for now
+ */
+static int osp_md_ref_del(const struct lu_env *env, struct dt_object *dt,
+			  struct thandle *th)
 {
-	CDEBUG(D_INFO, "ref del object "DFID"\n",
-	       PFID(&dt->do_lu.lo_header->loh_fid));
+	int rc = 0;
 
-	return 0;
+	if (is_only_remote_trans(th)) {
+		rc = __osp_md_ref_del(env, dt, th);
+
+		CDEBUG(D_INFO, "ref del "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
+
+	return rc;
 }
 
-static int osp_md_declare_ref_add(const struct lu_env *env,
-				  struct dt_object *dt, struct thandle *th)
+/**
+ * Add OUT_REF_ADD sub-request into the OUT RPC.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object on which to increase the reference count.
+ * \param[in] th	the transaction handle.
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int __osp_md_ref_add(const struct lu_env *env, struct dt_object *dt,
+			    struct thandle *th)
 {
 	struct dt_update_request	*update;
-	struct lu_fid			*fid;
 	int				rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: rc = %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -197,23 +338,82 @@ static int osp_md_declare_ref_add(const struct lu_env *env,
 		return PTR_ERR(update);
 	}
 
-	fid = (struct lu_fid *)lu_object_fid(&dt->do_lu);
+	rc = out_ref_add_pack(env, &update->dur_buf,
+			      lu_object_fid(&dt->do_lu),
+			      update->dur_batchid);
+
+	return rc;
+}
+
+/**
+ * Implementation of dt_object_operations::do_declare_ref_del
+ *
+ * For non-remote transaction, it will add an OUT_REF_ADD sub-request
+ * into the OUT RPC that will be flushed when the transaction start.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object on which to increase the reference count.
+ * \param[in] th	the transaction handle.
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int osp_md_declare_ref_add(const struct lu_env *env,
+				  struct dt_object *dt, struct thandle *th)
+{
+	int rc = 0;
+
+	if (!is_only_remote_trans(th)) {
+		rc = __osp_md_ref_add(env, dt, th);
 
-	rc = out_insert_update(env, update, OUT_REF_ADD, fid, 0, NULL, NULL);
+		CDEBUG(D_INFO, "declare ref add "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
 
 	return rc;
 }
 
-static int osp_md_object_ref_add(const struct lu_env *env,
-				 struct dt_object *dt,
-				 struct thandle *th)
+/**
+ * Implementation of dt_object_operations::do_ref_add
+ *
+ * For remote transaction, it will add an OUT_REF_ADD sub-request into
+ * the OUT RPC that will be flushed when the transaction stop.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object on which to increase the reference count
+ * \param[in] th	the transaction handle
+ *
+ * \retval		only return 0 for now
+ */
+static int osp_md_ref_add(const struct lu_env *env, struct dt_object *dt,
+			  struct thandle *th)
 {
-	CDEBUG(D_INFO, "ref add object "DFID"\n",
-	       PFID(&dt->do_lu.lo_header->loh_fid));
+	int rc = 0;
 
-	return 0;
+	if (is_only_remote_trans(th)) {
+		rc = __osp_md_ref_add(env, dt, th);
+
+		CDEBUG(D_INFO, "ref add "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
+
+	return rc;
 }
 
+/**
+ * Implementation of dt_object_operations::do_ah_init
+ *
+ * Initialize the allocation hint for object creation, which is usually called
+ * before the creation, and these hints (parent and child mode) will be sent to
+ * the remote Object Update Target (OUT) and used in the object create process,
+ * same as OSD object creation.
+ *
+ * \param[in] env	execution environment
+ * \param[in] ah	the hint to be initialized
+ * \param[in] parent	the parent of the object
+ * \param[in] child	the object to be created
+ * \param[in] child_mode the mode of the created object
+ */
 static void osp_md_ah_init(const struct lu_env *env,
 			   struct dt_allocation_hint *ah,
 			   struct dt_object *parent,
@@ -226,17 +426,24 @@ static void osp_md_ah_init(const struct lu_env *env,
 	ah->dah_mode = child_mode;
 }
 
-int osp_md_declare_attr_set(const struct lu_env *env, struct dt_object *dt,
-			    const struct lu_attr *attr, struct thandle *th)
+/**
+ * Add OUT_ATTR_SET sub-request into the OUT RPC.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object on which to set attributes
+ * \param[in] attr	attributes to be set
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+int __osp_md_attr_set(const struct lu_env *env, struct dt_object *dt,
+		      const struct lu_attr *attr, struct thandle *th)
 {
-	struct osp_thread_info		*osi = osp_env_info(env);
 	struct dt_update_request	*update;
-	struct lu_fid			*fid;
-	int				size = sizeof(struct obdo);
-	char				*buf;
 	int				rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -244,31 +451,86 @@ int osp_md_declare_attr_set(const struct lu_env *env, struct dt_object *dt,
 		return PTR_ERR(update);
 	}
 
-	osi->osi_obdo.o_valid = 0;
-	obdo_from_la(&osi->osi_obdo, (struct lu_attr *)attr,
-		     attr->la_valid);
-	lustre_set_wire_obdo(NULL, &osi->osi_obdo, &osi->osi_obdo);
-	obdo_cpu_to_le(&osi->osi_obdo, &osi->osi_obdo);
+	rc = out_attr_set_pack(env, &update->dur_buf,
+			       lu_object_fid(&dt->do_lu), attr,
+			       update->dur_batchid);
 
-	buf = (char *)&osi->osi_obdo;
-	fid = (struct lu_fid *)lu_object_fid(&dt->do_lu);
+	return rc;
+}
 
-	rc = out_insert_update(env, update, OUT_ATTR_SET, fid, 1, &size,
-			       (const char **)&buf);
+/**
+ * Implementation of dt_object_operations::do_declare_attr_get
+ *
+ * Declare setting attributes to the specified remote object.
+ *
+ * If the transaction is a non-remote transaction, then add the OUT_ATTR_SET
+ * sub-request into the OUT RPC that will be flushed when the transaction start.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object on which to set attributes
+ * \param[in] attr	attributes to be set
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+int osp_md_declare_attr_set(const struct lu_env *env, struct dt_object *dt,
+			    const struct lu_attr *attr, struct thandle *th)
+{
+	int rc = 0;
+
+	if (!is_only_remote_trans(th)) {
+		rc = __osp_md_attr_set(env, dt, attr, th);
+
+		CDEBUG(D_INFO, "declare attr set md_object "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
 
 	return rc;
 }
 
+/**
+ * Implementation of dt_object_operations::do_attr_set
+ *
+ * Set attributes to the specified remote object.
+ *
+ * If the transaction is a remote transaction, then add the OUT_ATTR_SET
+ * sub-request into the OUT RPC that will be flushed when the transaction stop.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to set attributes
+ * \param[in] attr	attributes to be set
+ * \param[in] th	the transaction handle
+ *
+ * \retval		only return 0 for now
+ */
 int osp_md_attr_set(const struct lu_env *env, struct dt_object *dt,
-		    const struct lu_attr *attr, struct thandle *th,
-		    struct lustre_capa *capa)
+		    const struct lu_attr *attr, struct thandle *th)
 {
-	CDEBUG(D_INFO, "attr set object "DFID"\n",
-	       PFID(&dt->do_lu.lo_header->loh_fid));
+	int rc = 0;
+
+	if (is_only_remote_trans(th)) {
+		rc = __osp_md_attr_set(env, dt, attr, th);
+
+		CDEBUG(D_INFO, "attr set md_object "DFID": rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), rc);
+	}
 
-	RETURN(0);
+	return rc;
 }
 
+/**
+ * Implementation of dt_object_operations::do_read_lock
+ *
+ * osp_md_object_{read,write}_lock() will only lock the remote object in the
+ * local cache, which uses the semaphore (opo_sem) inside the osp_object to
+ * lock the object. Note: it will not lock the object in the whole cluster,
+ * which relies on the LDLM lock.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be locked
+ * \param[in] role	lock role from MDD layer, see mdd_object_role().
+ */
 static void osp_md_object_read_lock(const struct lu_env *env,
 				    struct dt_object *dt, unsigned role)
 {
@@ -280,6 +542,15 @@ static void osp_md_object_read_lock(const struct lu_env *env,
 	LASSERT(obj->opo_owner == NULL);
 }
 
+/**
+ * Implementation of dt_object_operations::do_write_lock
+ *
+ * Lock the remote object in write mode.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be locked
+ * \param[in] role	lock role from MDD layer, see mdd_object_role().
+ */
 static void osp_md_object_write_lock(const struct lu_env *env,
 				     struct dt_object *dt, unsigned role)
 {
@@ -291,6 +562,14 @@ static void osp_md_object_write_lock(const struct lu_env *env,
 	obj->opo_owner = env;
 }
 
+/**
+ * Implementation of dt_object_operations::do_read_unlock
+ *
+ * Unlock the read lock of remote object.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be unlocked
+ */
 static void osp_md_object_read_unlock(const struct lu_env *env,
 				      struct dt_object *dt)
 {
@@ -299,6 +578,14 @@ static void osp_md_object_read_unlock(const struct lu_env *env,
 	up_read(&obj->opo_sem);
 }
 
+/**
+ * Implementation of dt_object_operations::do_write_unlock
+ *
+ * Unlock the write lock of remote object.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be unlocked
+ */
 static void osp_md_object_write_unlock(const struct lu_env *env,
 				       struct dt_object *dt)
 {
@@ -309,6 +596,14 @@ static void osp_md_object_write_unlock(const struct lu_env *env,
 	up_write(&obj->opo_sem);
 }
 
+/**
+ * Implementation of dt_object_operations::do_write_locked
+ *
+ * Test if the object is locked in write mode.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be tested
+ */
 static int osp_md_object_write_locked(const struct lu_env *env,
 				      struct dt_object *dt)
 {
@@ -317,9 +612,22 @@ static int osp_md_object_write_locked(const struct lu_env *env,
 	return obj->opo_owner == env;
 }
 
+/**
+ * Implementation of dt_index_operations::dio_lookup
+ *
+ * Look up record by key under a remote index object. It packs lookup update
+ * into RPC, sends to the remote OUT and waits for the lookup result.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	index object to lookup
+ * \param[out] rec	record in which to return lookup result
+ * \param[in] key	key of index which will be looked up
+ *
+ * \retval		1 if the lookup succeeds.
+ * \retval              negative errno if the lookup fails.
+ */
 static int osp_md_index_lookup(const struct lu_env *env, struct dt_object *dt,
-			       struct dt_rec *rec, const struct dt_key *key,
-			       struct lustre_capa *capa)
+			       struct dt_rec *rec, const struct dt_key *key)
 {
 	struct lu_buf		*lbuf	= &osp_env_info(env)->osi_lb2;
 	struct osp_device	*osp	= lu2osp_dev(dt->do_lu.lo_dev);
@@ -327,7 +635,6 @@ static int osp_md_index_lookup(const struct lu_env *env, struct dt_object *dt,
 	struct dt_update_request   *update;
 	struct object_update_reply *reply;
 	struct ptlrpc_request	   *req = NULL;
-	int			   size = strlen((char *)key) + 1;
 	struct lu_fid		   *fid;
 	int			   rc;
 	ENTRY;
@@ -336,20 +643,19 @@ static int osp_md_index_lookup(const struct lu_env *env, struct dt_object *dt,
 	 * just create an update buffer, instead of attaching the
 	 * update_remote list of the thandle.
 	 */
-	update = out_create_update_req(dt_dev);
+	update = dt_update_request_create(dt_dev);
 	if (IS_ERR(update))
 		RETURN(PTR_ERR(update));
 
-	rc = out_insert_update(env, update, OUT_INDEX_LOOKUP,
-			       lu_object_fid(&dt->do_lu),
-			       1, &size, (const char **)&key);
-	if (rc) {
+	rc = out_index_lookup_pack(env, &update->dur_buf,
+				   lu_object_fid(&dt->do_lu), rec, key);
+	if (rc != 0) {
 		CERROR("%s: Insert update error: rc = %d\n",
 		       dt_dev->dd_lu_dev.ld_obd->obd_name, rc);
 		GOTO(out, rc);
 	}
 
-	rc = out_remote_sync(env, osp->opd_obd->u.cli.cl_import, update, &req);
+	rc = osp_remote_sync(env, osp, update, &req, false);
 	if (rc < 0)
 		GOTO(out, rc);
 
@@ -365,7 +671,7 @@ static int osp_md_index_lookup(const struct lu_env *env, struct dt_object *dt,
 
 	rc = object_update_result_data_get(reply, lbuf, 0);
 	if (rc < 0)
-		GOTO(out, rc = size);
+		GOTO(out, rc);
 
 	if (lbuf->lb_len != sizeof(*fid)) {
 		CERROR("%s: lookup "DFID" %s wrong size %d\n",
@@ -376,7 +682,8 @@ static int osp_md_index_lookup(const struct lu_env *env, struct dt_object *dt,
 	}
 
 	fid = lbuf->lb_buf;
-	fid_le_to_cpu(fid, fid);
+	if (ptlrpc_rep_need_swab(req))
+		lustre_swab_lu_fid(fid);
 	if (!fid_is_sane(fid)) {
 		CERROR("%s: lookup "DFID" %s invalid fid "DFID"\n",
 		       dt_dev->dd_lu_dev.ld_obd->obd_name,
@@ -392,26 +699,33 @@ out:
 	if (req != NULL)
 		ptlrpc_req_finished(req);
 
-	out_destroy_update_req(update);
+	dt_update_request_destroy(update);
 
 	return rc;
 }
 
-static int osp_md_declare_insert(const struct lu_env *env,
+/**
+ * Add OUT_INDEX_INSERT sub-request into the OUT RPC.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object for which to insert index
+ * \param[in] rec	record of the index which will be inserted
+ * \param[in] key	key of the index which will be inserted
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int __osp_md_index_insert(const struct lu_env *env,
 				 struct dt_object *dt,
 				 const struct dt_rec *rec,
 				 const struct dt_key *key,
 				 struct thandle *th)
 {
 	struct dt_update_request *update;
-	struct lu_fid		 *fid;
-	struct lu_fid		 *rec_fid = (struct lu_fid *)rec;
-	int			 size[2] = {strlen((char *)key) + 1,
-						  sizeof(*rec_fid)};
-	const char		 *bufs[2] = {(char *)key, (char *)rec_fid};
 	int			 rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: rc = %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -419,41 +733,103 @@ static int osp_md_declare_insert(const struct lu_env *env,
 		return PTR_ERR(update);
 	}
 
-	fid = (struct lu_fid *)lu_object_fid(&dt->do_lu);
+	rc = out_index_insert_pack(env, &update->dur_buf,
+				   lu_object_fid(&dt->do_lu), rec, key,
+				   update->dur_batchid);
+	return rc;
+}
 
-	CDEBUG(D_INFO, "%s: insert index of "DFID" %s: "DFID"\n",
-	       dt->do_lu.lo_dev->ld_obd->obd_name,
-	       PFID(fid), (char *)key, PFID(rec_fid));
+/**
+ * Implementation of dt_index_operations::dio_declare_insert
+ *
+ * For non-remote transaction, it will add an OUT_INDEX_INSERT sub-request
+ * into the OUT RPC that will be flushed when the transaction start.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object for which to insert index
+ * \param[in] rec	record of the index which will be inserted
+ * \param[in] key	key of the index which will be inserted
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int osp_md_declare_index_insert(const struct lu_env *env,
+				       struct dt_object *dt,
+				       const struct dt_rec *rec,
+				       const struct dt_key *key,
+				       struct thandle *th)
+{
+	int rc = 0;
 
-	fid_cpu_to_le(rec_fid, rec_fid);
+	if (!is_only_remote_trans(th)) {
+		rc = __osp_md_index_insert(env, dt, rec, key, th);
+
+		CDEBUG(D_INFO, "declare index insert "DFID" key %s, rec "DFID
+		       ": rc = %d\n", PFID(&dt->do_lu.lo_header->loh_fid),
+		       (char *)key,
+		       PFID(((struct dt_insert_rec *)rec)->rec_fid), rc);
+	}
 
-	rc = out_insert_update(env, update, OUT_INDEX_INSERT, fid,
-			       ARRAY_SIZE(size), size, bufs);
 	return rc;
 }
 
+/**
+ * Implementation of dt_index_operations::dio_insert
+ *
+ * For remote transaction, it will add an OUT_INDEX_INSERT sub-request
+ * into the OUT RPC that will be flushed when the transaction stop.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object for which to insert index
+ * \param[in] rec	record of the index to be inserted
+ * \param[in] key	key of the index to be inserted
+ * \param[in] th	the transaction handle
+ * \param[in] ignore_quota quota enforcement for insert
+ *
+ * \retval		only return 0 for now
+ */
 static int osp_md_index_insert(const struct lu_env *env,
 			       struct dt_object *dt,
 			       const struct dt_rec *rec,
 			       const struct dt_key *key,
 			       struct thandle *th,
-			       struct lustre_capa *capa,
 			       int ignore_quota)
 {
-	return 0;
+	int rc = 0;
+
+	if (is_only_remote_trans(th)) {
+		rc = __osp_md_index_insert(env, dt, rec, key, th);
+
+		CDEBUG(D_INFO, "index insert "DFID" key %s, rec "DFID
+		       ": rc = %d\n", PFID(&dt->do_lu.lo_header->loh_fid),
+		       (char *)key,
+		       PFID(((struct dt_insert_rec *)rec)->rec_fid), rc);
+	}
+
+	return rc;
 }
 
-static int osp_md_declare_delete(const struct lu_env *env,
+/**
+ * Add OUT_INDEX_DELETE sub-request into the OUT RPC.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object for which to delete index
+ * \param[in] key	key of the index
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int __osp_md_index_delete(const struct lu_env *env,
 				 struct dt_object *dt,
 				 const struct dt_key *key,
 				 struct thandle *th)
 {
 	struct dt_update_request *update;
-	struct lu_fid *fid;
-	int size = strlen((char *)key) + 1;
-	int rc;
+	int			 rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: rc = %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -461,134 +837,259 @@ static int osp_md_declare_delete(const struct lu_env *env,
 		return PTR_ERR(update);
 	}
 
-	fid = (struct lu_fid *)lu_object_fid(&dt->do_lu);
-
-	rc = out_insert_update(env, update, OUT_INDEX_DELETE, fid, 1, &size,
-			       (const char **)&key);
-
+	rc = out_index_delete_pack(env, &update->dur_buf,
+				   lu_object_fid(&dt->do_lu), key,
+				   update->dur_batchid);
 	return rc;
 }
 
-static int osp_md_index_delete(const struct lu_env *env,
-			       struct dt_object *dt,
-			       const struct dt_key *key,
-			       struct thandle *th,
-			       struct lustre_capa *capa)
+/**
+ * Implementation of dt_index_operations::dio_declare_delete
+ *
+ * For non-remote transaction, it will add an OUT_INDEX_DELETE sub-request
+ * into the OUT RPC that will be flushed when the transaction start.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object for which to delete index
+ * \param[in] key	key of the index
+ * \param[in] th	the transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
+static int osp_md_declare_index_delete(const struct lu_env *env,
+				       struct dt_object *dt,
+				       const struct dt_key *key,
+				       struct thandle *th)
 {
-	CDEBUG(D_INFO, "index delete "DFID" %s\n",
-	       PFID(&dt->do_lu.lo_header->loh_fid), (char *)key);
+	int rc = 0;
 
-	return 0;
+	if (!is_only_remote_trans(th)) {
+		rc = __osp_md_index_delete(env, dt, key, th);
+
+		CDEBUG(D_INFO, "declare index delete "DFID" %s: rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), (char *)key, rc);
+	}
+
+	return rc;
 }
 
 /**
- * Creates or initializes iterator context.
+ * Implementation of dt_index_operations::dio_delete
+ *
+ * For remote transaction, it will add an OUT_INDEX_DELETE sub-request
+ * into the OUT RPC that will be flushed when the transaction stop.
  *
- * Note: for OSP, these index iterate api is only used to check
- * whether the directory is empty now (see mdd_dir_is_empty).
- * Since dir_empty will be return by OUT_ATTR_GET(see osp_attr_get/
- * out_attr_get). So the implementation of these iterator is simplied
- * to make mdd_dir_is_empty happy. The real iterator should be
- * implemented, if we need it one day.
+ * \param[in] env	execution environment
+ * \param[in] dt	object for which to delete index
+ * \param[in] key	key of the index which will be deleted
+ * \param[in] th	the transaction handle
+ *
+ * \retval		only return 0 for now
  */
-static struct dt_it *osp_it_init(const struct lu_env *env,
-				 struct dt_object *dt,
-				 __u32 attr,
-				struct lustre_capa *capa)
+static int osp_md_index_delete(const struct lu_env *env,
+			       struct dt_object *dt,
+			       const struct dt_key *key,
+			       struct thandle *th)
 {
-	lu_object_get(&dt->do_lu);
-	return (struct dt_it *)dt;
-}
+	int rc = 0;
 
-static void osp_it_fini(const struct lu_env *env, struct dt_it *di)
-{
-	struct dt_object *dt = (struct dt_object *)di;
-	lu_object_put(env, &dt->do_lu);
-}
+	if (is_only_remote_trans(th)) {
+		rc = __osp_md_index_delete(env, dt, key, th);
 
-static int osp_it_get(const struct lu_env *env,
-		      struct dt_it *di, const struct dt_key *key)
-{
-	return 1;
-}
+		CDEBUG(D_INFO, "index delete "DFID" %s: rc = %d\n",
+		       PFID(&dt->do_lu.lo_header->loh_fid), (char *)key, rc);
+	}
 
-static void osp_it_put(const struct lu_env *env, struct dt_it *di)
-{
-	return;
+	return rc;
 }
 
-static int osp_it_next(const struct lu_env *env, struct dt_it *di)
+/**
+ * Implementation of dt_index_operations::dio_it.next
+ *
+ * Advance the pointer of the iterator to the next entry. It shares a similar
+ * internal implementation with osp_orphan_it_next(), which is being used for
+ * remote orphan index object. This method will be used for remote directory.
+ *
+ * \param[in] env	execution environment
+ * \param[in] di	iterator of this iteration
+ *
+ * \retval		0 if the pointer is advanced successfuly.
+ * \retval		1 if it reaches to the end of the index object.
+ * \retval		negative errno if the pointer cannot be advanced.
+ */
+static int osp_md_index_it_next(const struct lu_env *env, struct dt_it *di)
 {
-	struct dt_object *dt = (struct dt_object *)di;
-	struct osp_object *o = dt2osp_obj(dt);
+	struct osp_it		*it = (struct osp_it *)di;
+	struct lu_idxpage	*idxpage;
+	struct lu_dirent	*ent = (struct lu_dirent *)it->ooi_ent;
+	int			rc;
+	ENTRY;
 
-	if (o->opo_empty)
-		return 1;
+again:
+	idxpage = it->ooi_cur_idxpage;
+	if (idxpage != NULL) {
+		if (idxpage->lip_nr == 0)
+			RETURN(1);
+
+		it->ooi_pos_ent++;
+		if (ent == NULL) {
+			it->ooi_ent =
+			      (struct lu_dirent *)idxpage->lip_entries;
+			RETURN(0);
+		} else if (le16_to_cpu(ent->lde_reclen) != 0 &&
+			   it->ooi_pos_ent < idxpage->lip_nr) {
+			ent = (struct lu_dirent *)(((char *)ent) +
+					le16_to_cpu(ent->lde_reclen));
+			it->ooi_ent = ent;
+			RETURN(0);
+		} else {
+			it->ooi_ent = NULL;
+		}
+	}
 
-	return 0;
+	rc = osp_it_next_page(env, di);
+	if (rc == 0)
+		goto again;
+
+	RETURN(rc);
 }
 
+/**
+ * Implementation of dt_index_operations::dio_it.key
+ *
+ * Get the key at current iterator poisiton. These iteration methods
+ * (dio_it) will only be used for iterating the remote directory, so
+ * the key is the name of the directory entry.
+ *
+ * \param[in] env	execution environment
+ * \param[in] di	iterator of this iteration
+ *
+ * \retval		name of the current entry
+ */
 static struct dt_key *osp_it_key(const struct lu_env *env,
 				 const struct dt_it *di)
 {
-	LBUG();
-	return NULL;
+	struct osp_it		*it = (struct osp_it *)di;
+	struct lu_dirent	*ent = (struct lu_dirent *)it->ooi_ent;
+
+	return (struct dt_key *)ent->lde_name;
 }
 
+/**
+ * Implementation of dt_index_operations::dio_it.key_size
+ *
+ * Get the key size at current iterator poisiton. These iteration methods
+ * (dio_it) will only be used for iterating the remote directory, so the key
+ * size is the name size of the directory entry.
+ *
+ * \param[in] env	execution environment
+ * \param[in] di	iterator of this iteration
+ *
+ * \retval		name size of the current entry
+ */
+
 static int osp_it_key_size(const struct lu_env *env, const struct dt_it *di)
 {
-	LBUG();
-	return 0;
-}
+	struct osp_it		*it = (struct osp_it *)di;
+	struct lu_dirent	*ent = (struct lu_dirent *)it->ooi_ent;
 
-static int osp_it_rec(const struct lu_env *env, const struct dt_it *di,
-		      struct dt_rec *lde, __u32 attr)
-{
-	LBUG();
-	return 0;
+	return (int)le16_to_cpu(ent->lde_namelen);
 }
 
-static __u64 osp_it_store(const struct lu_env *env, const struct dt_it *di)
+/**
+ * Implementation of dt_index_operations::dio_it.rec
+ *
+ * Get the record at current iterator position. These iteration methods
+ * (dio_it) will only be used for iterating the remote directory, so it
+ * uses lu_dirent_calc_size() to calculate the record size.
+ *
+ * \param[in] env	execution environment
+ * \param[in] di	iterator of this iteration
+ * \param[out] rec	the record to be returned
+ * \param[in] attr	attributes of the index object, so it knows
+ *                      how to pack the entry.
+ *
+ * \retval		only return 0 for now
+ */
+static int osp_md_index_it_rec(const struct lu_env *env, const struct dt_it *di,
+			       struct dt_rec *rec, __u32 attr)
 {
-	LBUG();
+	struct osp_it		*it = (struct osp_it *)di;
+	struct lu_dirent	*ent = (struct lu_dirent *)it->ooi_ent;
+	size_t			reclen;
+
+	reclen = lu_dirent_calc_size(le16_to_cpu(ent->lde_namelen), attr);
+	memcpy(rec, ent, reclen);
 	return 0;
 }
 
+/**
+ * Implementation of dt_index_operations::dio_it.load
+ *
+ * Locate the iteration cursor to the specified position (cookie).
+ *
+ * \param[in] env	pointer to the thread context
+ * \param[in] di	pointer to the iteration structure
+ * \param[in] hash	the specified position
+ *
+ * \retval		positive number for locating to the exactly position
+ *			or the next
+ * \retval		0 for arriving at the end of the iteration
+ * \retval		negative error number on failure
+ */
 static int osp_it_load(const struct lu_env *env, const struct dt_it *di,
 		       __u64 hash)
 {
-	LBUG();
-	return 0;
-}
+	struct osp_it	*it	= (struct osp_it *)di;
+	int		 rc;
 
-static int osp_it_key_rec(const struct lu_env *env, const struct dt_it *di,
-			  void *key_rec)
-{
-	LBUG();
-	return 0;
+	it->ooi_next = hash;
+	rc = osp_md_index_it_next(env, (struct dt_it *)di);
+	if (rc == 1)
+		return 0;
+
+	if (rc == 0)
+		return 1;
+
+	return rc;
 }
 
-static const struct dt_index_operations osp_md_index_ops = {
+const struct dt_index_operations osp_md_index_ops = {
 	.dio_lookup         = osp_md_index_lookup,
-	.dio_declare_insert = osp_md_declare_insert,
+	.dio_declare_insert = osp_md_declare_index_insert,
 	.dio_insert         = osp_md_index_insert,
-	.dio_declare_delete = osp_md_declare_delete,
+	.dio_declare_delete = osp_md_declare_index_delete,
 	.dio_delete         = osp_md_index_delete,
 	.dio_it     = {
 		.init     = osp_it_init,
 		.fini     = osp_it_fini,
 		.get      = osp_it_get,
 		.put      = osp_it_put,
-		.next     = osp_it_next,
+		.next     = osp_md_index_it_next,
 		.key      = osp_it_key,
 		.key_size = osp_it_key_size,
-		.rec      = osp_it_rec,
+		.rec      = osp_md_index_it_rec,
 		.store    = osp_it_store,
 		.load     = osp_it_load,
 		.key_rec  = osp_it_key_rec,
 	}
 };
 
+/**
+ * Implementation of dt_object_operations::do_index_try
+ *
+ * Try to initialize the index API pointer for the given object. This
+ * is the entry point of the index API, i.e. we must call this method
+ * to initialize the index object before calling other index methods.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	index object to be initialized
+ * \param[in] feat	the index feature of the object
+ *
+ * \retval		0 if the initialization succeeds.
+ * \retval              negative errno if the initialization fails.
+ */
 static int osp_md_index_try(const struct lu_env *env,
 			    struct dt_object *dt,
 			    const struct dt_index_features *feat)
@@ -597,6 +1098,21 @@ static int osp_md_index_try(const struct lu_env *env,
 	return 0;
 }
 
+/**
+ * Implementation of dt_object_operations::do_object_lock
+ *
+ * Enqueue a lock (by ldlm_cli_enqueue()) of remote object on the remote MDT,
+ * which will lock the object in the global namespace.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be locked
+ * \param[out] lh	lock handle
+ * \param[in] einfo	enqueue information
+ * \param[in] policy	lock policy
+ *
+ * \retval		ELDLM_OK if locking the object succeeds.
+ * \retval		negative errno if locking fails.
+ */
 static int osp_md_object_lock(const struct lu_env *env,
 			      struct dt_object *dt,
 			      struct lustre_handle *lh,
@@ -634,6 +1150,18 @@ static int osp_md_object_lock(const struct lu_env *env,
 	return rc == ELDLM_OK ? 0 : -EIO;
 }
 
+/**
+ * Implementation of dt_object_operations::do_object_unlock
+ *
+ * Cancel a lock of a remote object.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be unlocked
+ * \param[in] einfo	lock enqueue information
+ * \param[in] policy	lock policy
+ *
+ * \retval		Only return 0 for now.
+ */
 static int osp_md_object_unlock(const struct lu_env *env,
 				struct dt_object *dt,
 				struct ldlm_enqueue_info *einfo,
@@ -656,9 +1184,9 @@ struct dt_object_operations osp_md_obj_ops = {
 	.do_declare_create    = osp_md_declare_object_create,
 	.do_create            = osp_md_object_create,
 	.do_declare_ref_add   = osp_md_declare_ref_add,
-	.do_ref_add           = osp_md_object_ref_add,
-	.do_declare_ref_del   = osp_md_declare_object_ref_del,
-	.do_ref_del           = osp_md_object_ref_del,
+	.do_ref_add           = osp_md_ref_add,
+	.do_declare_ref_del   = osp_md_declare_ref_del,
+	.do_ref_del           = osp_md_ref_del,
 	.do_declare_destroy   = osp_declare_object_destroy,
 	.do_destroy           = osp_object_destroy,
 	.do_ah_init           = osp_md_ah_init,
@@ -668,24 +1196,37 @@ struct dt_object_operations osp_md_obj_ops = {
 	.do_xattr_get         = osp_xattr_get,
 	.do_declare_xattr_set = osp_declare_xattr_set,
 	.do_xattr_set         = osp_xattr_set,
+	.do_declare_xattr_del = osp_declare_xattr_del,
+	.do_xattr_del         = osp_xattr_del,
 	.do_index_try         = osp_md_index_try,
 	.do_object_lock       = osp_md_object_lock,
 	.do_object_unlock     = osp_md_object_unlock,
 };
 
+/**
+ * Implementation of dt_body_operations::dbo_declare_write
+ *
+ * Declare an object write. In DNE phase I, it will pack the write
+ * object update into the RPC.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be written
+ * \param[in] buf	buffer to write which includes an embedded size field
+ * \param[in] pos	offet in the object to start writing at
+ * \param[in] th	transaction handle
+ *
+ * \retval		0 if the insertion succeeds.
+ * \retval		negative errno if the insertion fails.
+ */
 static ssize_t osp_md_declare_write(const struct lu_env *env,
 				    struct dt_object *dt,
 				    const struct lu_buf *buf,
 				    loff_t pos, struct thandle *th)
 {
 	struct dt_update_request  *update;
-	struct lu_fid		  *fid;
-	int			  sizes[2] = {buf->lb_len, sizeof(pos)};
-	const char		  *bufs[2] = {(char *)buf->lb_buf,
-					      (char *)&pos};
 	ssize_t			  rc;
 
-	update = out_find_create_update_loc(th, dt);
+	update = dt_update_request_find_or_create(th, dt);
 	if (IS_ERR(update)) {
 		CERROR("%s: Get OSP update buf failed: rc = %d\n",
 		       dt->do_lu.lo_dev->ld_obd->obd_name,
@@ -693,21 +1234,34 @@ static ssize_t osp_md_declare_write(const struct lu_env *env,
 		return PTR_ERR(update);
 	}
 
-	pos = cpu_to_le64(pos);
-	bufs[1] = (char *)&pos;
-	fid = (struct lu_fid *)lu_object_fid(&dt->do_lu);
-	rc = out_insert_update(env, update, OUT_WRITE, fid,
-			       ARRAY_SIZE(sizes), sizes, bufs);
+	rc = out_write_pack(env, &update->dur_buf, lu_object_fid(&dt->do_lu),
+			    buf, pos, update->dur_batchid);
 
 	return rc;
 
 }
 
+/**
+ * Implementation of dt_body_operations::dbo_write
+ *
+ * Return the buffer size. In DNE phase I, remote updates
+ * are actually executed during transaction start, the buffer has
+ * already been written when this method is being called.
+ *
+ * \param[in] env	execution environment
+ * \param[in] dt	object to be written
+ * \param[in] buf	buffer to write which includes an embedded size field
+ * \param[in] pos	offet in the object to start writing at
+ * \param[in] th	transaction handle
+ * \param[in] ignore_quota quota enforcement for this write
+ *
+ * \retval		the buffer size in bytes.
+ */
 static ssize_t osp_md_write(const struct lu_env *env, struct dt_object *dt,
 			    const struct lu_buf *buf, loff_t *pos,
-			    struct thandle *handle,
-			    struct lustre_capa *capa, int ignore_quota)
+			    struct thandle *handle, int ignore_quota)
 {
+	*pos += buf->lb_len;
 	return buf->lb_len;
 }