X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Ftarget%2Ftgt_lastrcvd.c;h=245799384a5acf0aba3d66a5d3123b52a34cdefa;hp=b8da83fdc1d4af9f17c3b4c4ddc6fc7596323e3b;hb=ecd28d9b6cb691bda8184a7e07f1acc1ccded391;hpb=08aa217ce49aba1ded52e0f7adb8a607035123fd

diff --git a/lustre/target/tgt_lastrcvd.c b/lustre/target/tgt_lastrcvd.c
index b8da83f..2457993 100644
--- a/lustre/target/tgt_lastrcvd.c
+++ b/lustre/target/tgt_lastrcvd.c
@@ -27,7 +27,7 @@
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2012, Intel Corporation.
+ * Copyright (c) 2011, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -112,6 +112,9 @@ int tgt_client_data_read(const struct lu_env *env, struct lu_target *tgt,
 	if (rc == 0) {
 		check_lcd(tgt->lut_obd->obd_name, index, &tti->tti_lcd);
 		lcd_le_to_cpu(&tti->tti_lcd, lcd);
+		lcd->lcd_last_result = ptlrpc_status_ntoh(lcd->lcd_last_result);
+		lcd->lcd_last_close_result =
+			ptlrpc_status_ntoh(lcd->lcd_last_close_result);
 	}
 
 	CDEBUG(D_INFO, "%s: read lcd @%lld uuid = %s, last_transno = "LPU64
@@ -124,7 +127,6 @@ int tgt_client_data_read(const struct lu_env *env, struct lu_target *tgt,
 	       lcd->lcd_last_close_result, rc);
 	return rc;
 }
-EXPORT_SYMBOL(tgt_client_data_read);
 
 int tgt_client_data_write(const struct lu_env *env, struct lu_target *tgt,
 			  struct lsd_client_data *lcd, loff_t *off,
@@ -132,17 +134,20 @@ int tgt_client_data_write(const struct lu_env *env, struct lu_target *tgt,
 {
 	struct tgt_thread_info *tti = tgt_th_info(env);
 
+	lcd->lcd_last_result = ptlrpc_status_hton(lcd->lcd_last_result);
+	lcd->lcd_last_close_result =
+		ptlrpc_status_hton(lcd->lcd_last_close_result);
 	lcd_cpu_to_le(lcd, &tti->tti_lcd);
 	tti_buf_lcd(tti);
 
 	return dt_record_write(env, tgt->lut_last_rcvd, &tti->tti_buf, off, th);
 }
-EXPORT_SYMBOL(tgt_client_data_write);
 
 /**
  * Update client data in last_rcvd
  */
-int tgt_client_data_update(const struct lu_env *env, struct obd_export *exp)
+static int tgt_client_data_update(const struct lu_env *env,
+				  struct obd_export *exp)
 {
 	struct tg_export_data	*ted = &exp->exp_target_data;
 	struct lu_target	*tgt = class_exp2tgt(exp);
@@ -156,8 +161,9 @@ int tgt_client_data_update(const struct lu_env *env, struct obd_export *exp)
 	if (IS_ERR(th))
 		RETURN(PTR_ERR(th));
 
+	tti_buf_lcd(tti);
 	rc = dt_declare_record_write(env, tgt->lut_last_rcvd,
-				     sizeof(struct lsd_client_data),
+				     &tti->tti_buf,
 				     ted->ted_lr_off, th);
 	if (rc)
 		GOTO(out, rc);
@@ -210,7 +216,6 @@ int tgt_server_data_read(const struct lu_env *env, struct lu_target *tgt)
 	       tgt->lut_lsd.lsd_uuid, tgt->lut_lsd.lsd_last_transno, rc);
         return rc;
 }
-EXPORT_SYMBOL(tgt_server_data_read);
 
 int tgt_server_data_write(const struct lu_env *env, struct lu_target *tgt,
 			  struct thandle *th)
@@ -233,7 +238,6 @@ int tgt_server_data_write(const struct lu_env *env, struct lu_target *tgt,
 
 	RETURN(rc);
 }
-EXPORT_SYMBOL(tgt_server_data_write);
 
 /**
  * Update server data in last_rcvd
@@ -263,9 +267,9 @@ int tgt_server_data_update(const struct lu_env *env, struct lu_target *tgt,
 
 	th->th_sync = sync;
 
+	tti_buf_lsd(tti);
 	rc = dt_declare_record_write(env, tgt->lut_last_rcvd,
-				     sizeof(struct lr_server_data),
-				     tti->tti_off, th);
+				     &tti->tti_buf, tti->tti_off, th);
 	if (rc)
 		GOTO(out, rc);
 
@@ -319,9 +323,9 @@ cleanup:
 
 	RETURN(rc);
 }
-EXPORT_SYMBOL(tgt_truncate_last_rcvd);
 
-void tgt_client_epoch_update(const struct lu_env *env, struct obd_export *exp)
+static void tgt_client_epoch_update(const struct lu_env *env,
+				    struct obd_export *exp)
 {
 	struct lsd_client_data	*lcd = exp->exp_target_data.ted_lcd;
 	struct lu_target	*tgt = class_exp2tgt(exp);
@@ -342,7 +346,7 @@ void tgt_boot_epoch_update(struct lu_target *tgt)
 	struct lu_env		 env;
 	struct ptlrpc_request	*req;
 	__u32			 start_epoch;
-	cfs_list_t		 client_list;
+	struct list_head	 client_list;
 	int			 rc;
 
 	if (tgt->lut_obd->obd_stopping)
@@ -361,33 +365,32 @@ void tgt_boot_epoch_update(struct lu_target *tgt)
 	tgt->lut_lsd.lsd_start_epoch = start_epoch;
 	spin_unlock(&tgt->lut_translock);
 
-	CFS_INIT_LIST_HEAD(&client_list);
+	INIT_LIST_HEAD(&client_list);
 	/**
 	 * The recovery is not yet finished and final queue can still be updated
 	 * with resend requests. Move final list to separate one for processing
 	 */
 	spin_lock(&tgt->lut_obd->obd_recovery_task_lock);
-	cfs_list_splice_init(&tgt->lut_obd->obd_final_req_queue, &client_list);
+	list_splice_init(&tgt->lut_obd->obd_final_req_queue, &client_list);
 	spin_unlock(&tgt->lut_obd->obd_recovery_task_lock);
 
 	/**
 	 * go through list of exports participated in recovery and
 	 * set new epoch for them
 	 */
-	cfs_list_for_each_entry(req, &client_list, rq_list) {
+	list_for_each_entry(req, &client_list, rq_list) {
 		LASSERT(!req->rq_export->exp_delayed);
 		if (!req->rq_export->exp_vbr_failed)
 			tgt_client_epoch_update(&env, req->rq_export);
 	}
 	/** return list back at once */
 	spin_lock(&tgt->lut_obd->obd_recovery_task_lock);
-	cfs_list_splice_init(&client_list, &tgt->lut_obd->obd_final_req_queue);
+	list_splice_init(&client_list, &tgt->lut_obd->obd_final_req_queue);
 	spin_unlock(&tgt->lut_obd->obd_recovery_task_lock);
 	/** update server epoch */
 	tgt_server_data_update(&env, tgt, 1);
 	lu_env_fini(&env);
 }
-EXPORT_SYMBOL(tgt_boot_epoch_update);
 
 /**
  * commit callback, need to update last_commited value
@@ -399,8 +402,8 @@ struct tgt_last_committed_callback {
 	__u64			 llcc_transno;
 };
 
-void tgt_cb_last_committed(struct lu_env *env, struct thandle *th,
-			   struct dt_txn_commit_cb *cb, int err)
+static void tgt_cb_last_committed(struct lu_env *env, struct thandle *th,
+				  struct dt_txn_commit_cb *cb, int err)
 {
 	struct tgt_last_committed_callback *ccb;
 
@@ -445,9 +448,8 @@ int tgt_last_commit_cb_add(struct thandle *th, struct lu_target *tgt,
 
 	dcb = &ccb->llcc_cb;
 	dcb->dcb_func = tgt_cb_last_committed;
-	CFS_INIT_LIST_HEAD(&dcb->dcb_linkage);
-	strncpy(dcb->dcb_name, "tgt_cb_last_committed", MAX_COMMIT_CB_STR_LEN);
-	dcb->dcb_name[MAX_COMMIT_CB_STR_LEN - 1] = '\0';
+	INIT_LIST_HEAD(&dcb->dcb_linkage);
+	strlcpy(dcb->dcb_name, "tgt_cb_last_committed", sizeof(dcb->dcb_name));
 
 	rc = dt_trans_cb_add(th, dcb);
 	if (rc) {
@@ -455,21 +457,20 @@ int tgt_last_commit_cb_add(struct thandle *th, struct lu_target *tgt,
 		OBD_FREE_PTR(ccb);
 	}
 
-	if ((exp->exp_connect_flags & OBD_CONNECT_LIGHTWEIGHT) != 0)
+	if (exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
 		/* report failure to force synchronous operation */
 		return -EPERM;
 
 	return rc;
 }
-EXPORT_SYMBOL(tgt_last_commit_cb_add);
 
 struct tgt_new_client_callback {
 	struct dt_txn_commit_cb	 lncc_cb;
 	struct obd_export	*lncc_exp;
 };
 
-void tgt_cb_new_client(struct lu_env *env, struct thandle *th,
-		       struct dt_txn_commit_cb *cb, int err)
+static void tgt_cb_new_client(struct lu_env *env, struct thandle *th,
+			      struct dt_txn_commit_cb *cb, int err)
 {
 	struct tgt_new_client_callback *ccb;
 
@@ -482,7 +483,12 @@ void tgt_cb_new_client(struct lu_env *env, struct thandle *th,
 	       ccb->lncc_exp->exp_client_uuid.uuid);
 
 	spin_lock(&ccb->lncc_exp->exp_lock);
-	ccb->lncc_exp->exp_need_sync = 0;
+	/* XXX: Currently, we use per-export based sync/async policy for
+	 *	the update via OUT RPC, it is coarse-grained policy, and
+	 *	will be changed as per-request based by DNE II patches. */
+	if (!ccb->lncc_exp->exp_keep_sync)
+		ccb->lncc_exp->exp_need_sync = 0;
+
 	spin_unlock(&ccb->lncc_exp->exp_lock);
 	class_export_cb_put(ccb->lncc_exp);
 
@@ -503,9 +509,8 @@ int tgt_new_client_cb_add(struct thandle *th, struct obd_export *exp)
 
 	dcb = &ccb->lncc_cb;
 	dcb->dcb_func = tgt_cb_new_client;
-	CFS_INIT_LIST_HEAD(&dcb->dcb_linkage);
-	strncpy(dcb->dcb_name, "tgt_cb_new_client", MAX_COMMIT_CB_STR_LEN);
-	dcb->dcb_name[MAX_COMMIT_CB_STR_LEN - 1] = '\0';
+	INIT_LIST_HEAD(&dcb->dcb_linkage);
+	strlcpy(dcb->dcb_name, "tgt_cb_new_client", sizeof(dcb->dcb_name));
 
 	rc = dt_trans_cb_add(th, dcb);
 	if (rc) {
@@ -535,7 +540,7 @@ int tgt_client_new(const struct lu_env *env, struct obd_export *exp)
 
 	mutex_init(&ted->ted_lcd_lock);
 
-	if ((exp->exp_connect_flags & OBD_CONNECT_LIGHTWEIGHT) != 0)
+	if (exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
 		RETURN(0);
 
 	/* the bitmap operations can handle cl_idx > sizeof(long) * 8, so
@@ -599,7 +604,7 @@ int tgt_client_add(const struct lu_env *env,  struct obd_export *exp, int idx)
 	LASSERTF(idx >= 0, "%d\n", idx);
 
 	if (!strcmp(ted->ted_lcd->lcd_uuid, tgt->lut_obd->obd_uuid.uuid) ||
-	    (exp->exp_connect_flags & OBD_CONNECT_LIGHTWEIGHT) != 0)
+	    exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
 		RETURN(0);
 
 	if (test_and_set_bit(idx, tgt->lut_client_bitmap)) {
@@ -621,7 +626,6 @@ int tgt_client_add(const struct lu_env *env,  struct obd_export *exp, int idx)
 
 	RETURN(0);
 }
-EXPORT_SYMBOL(tgt_client_add);
 
 int tgt_client_del(const struct lu_env *env, struct obd_export *exp)
 {
@@ -636,7 +640,7 @@ int tgt_client_del(const struct lu_env *env, struct obd_export *exp)
 	/* XXX if lcd_uuid were a real obd_uuid, I could use obd_uuid_equals */
 	if (!strcmp((char *)ted->ted_lcd->lcd_uuid,
 		    (char *)tgt->lut_obd->obd_uuid.uuid) ||
-	    (exp->exp_connect_flags & OBD_CONNECT_LIGHTWEIGHT) != 0)
+	    exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
 		RETURN(0);
 
 	CDEBUG(D_INFO, "%s: del client at idx %u, off %lld, UUID '%s'\n",
@@ -678,3 +682,568 @@ int tgt_client_del(const struct lu_env *env, struct obd_export *exp)
 	RETURN(rc);
 }
 EXPORT_SYMBOL(tgt_client_del);
+
+/*
+ * last_rcvd & last_committed update callbacks
+ */
+static int tgt_last_rcvd_update(const struct lu_env *env, struct lu_target *tgt,
+				struct dt_object *obj, __u64 opdata,
+				struct thandle *th, struct ptlrpc_request *req)
+{
+	struct tgt_thread_info	*tti = tgt_th_info(env);
+	struct tg_export_data	*ted;
+	__u64			*transno_p;
+	int			 rc = 0;
+	bool			 lw_client, update = false;
+
+	ENTRY;
+
+	ted = &req->rq_export->exp_target_data;
+
+	lw_client = exp_connect_flags(req->rq_export) & OBD_CONNECT_LIGHTWEIGHT;
+	if (ted->ted_lr_idx < 0 && !lw_client)
+		/* ofd connect may cause transaction before export has
+		 * last_rcvd slot */
+		RETURN(0);
+
+	tti->tti_transno = lustre_msg_get_transno(req->rq_reqmsg);
+
+	spin_lock(&tgt->lut_translock);
+	if (th->th_result != 0) {
+		if (tti->tti_transno != 0) {
+			CERROR("%s: replay transno "LPU64" failed: rc = %d\n",
+			       tgt_name(tgt), tti->tti_transno, th->th_result);
+		}
+	} else if (tti->tti_transno == 0) {
+		tti->tti_transno = ++tgt->lut_last_transno;
+	} else {
+		/* should be replay */
+		if (tti->tti_transno > tgt->lut_last_transno)
+			tgt->lut_last_transno = tti->tti_transno;
+	}
+	spin_unlock(&tgt->lut_translock);
+
+	/** VBR: set new versions */
+	if (th->th_result == 0 && obj != NULL)
+		dt_version_set(env, obj, tti->tti_transno, th);
+
+	/* filling reply data */
+	CDEBUG(D_INODE, "transno = "LPU64", last_committed = "LPU64"\n",
+	       tti->tti_transno, tgt->lut_obd->obd_last_committed);
+
+	req->rq_transno = tti->tti_transno;
+	lustre_msg_set_transno(req->rq_repmsg, tti->tti_transno);
+
+	/* if can't add callback, do sync write */
+	th->th_sync |= !!tgt_last_commit_cb_add(th, tgt, req->rq_export,
+						tti->tti_transno);
+
+	if (lw_client) {
+		/* All operations performed by LW clients are synchronous and
+		 * we store the committed transno in the last_rcvd header */
+		spin_lock(&tgt->lut_translock);
+		if (tti->tti_transno > tgt->lut_lsd.lsd_last_transno) {
+			tgt->lut_lsd.lsd_last_transno = tti->tti_transno;
+			update = true;
+		}
+		spin_unlock(&tgt->lut_translock);
+		/* Although lightweight (LW) connections have no slot in
+		 * last_rcvd, we still want to maintain the in-memory
+		 * lsd_client_data structure in order to properly handle reply
+		 * reconstruction. */
+	} else if (ted->ted_lr_off == 0) {
+		CERROR("%s: client idx %d has offset %lld\n",
+		       tgt_name(tgt), ted->ted_lr_idx, ted->ted_lr_off);
+		RETURN(-EINVAL);
+	}
+
+	/* if the export has already been disconnected, we have no last_rcvd
+	 * slot, update server data with latest transno then */
+	if (ted->ted_lcd == NULL) {
+		CWARN("commit transaction for disconnected client %s: rc %d\n",
+		      req->rq_export->exp_client_uuid.uuid, rc);
+		GOTO(srv_update, rc = 0);
+	}
+
+	mutex_lock(&ted->ted_lcd_lock);
+	LASSERT(ergo(tti->tti_transno == 0, th->th_result != 0));
+	if (lustre_msg_get_opc(req->rq_reqmsg) == MDS_CLOSE ||
+	    lustre_msg_get_opc(req->rq_reqmsg) == MDS_DONE_WRITING) {
+		transno_p = &ted->ted_lcd->lcd_last_close_transno;
+		ted->ted_lcd->lcd_last_close_xid = req->rq_xid;
+		ted->ted_lcd->lcd_last_close_result = th->th_result;
+	} else {
+		/* VBR: save versions in last_rcvd for reconstruct. */
+		__u64 *pre_versions = lustre_msg_get_versions(req->rq_repmsg);
+
+		if (pre_versions) {
+			ted->ted_lcd->lcd_pre_versions[0] = pre_versions[0];
+			ted->ted_lcd->lcd_pre_versions[1] = pre_versions[1];
+			ted->ted_lcd->lcd_pre_versions[2] = pre_versions[2];
+			ted->ted_lcd->lcd_pre_versions[3] = pre_versions[3];
+		}
+		transno_p = &ted->ted_lcd->lcd_last_transno;
+		ted->ted_lcd->lcd_last_xid = req->rq_xid;
+		ted->ted_lcd->lcd_last_result = th->th_result;
+		/* XXX: lcd_last_data is __u32 but intent_dispostion is __u64,
+		 * see struct ldlm_reply->lock_policy_res1; */
+		ted->ted_lcd->lcd_last_data = opdata;
+	}
+
+	/* Update transno in slot only if non-zero number, i.e. no errors */
+	if (likely(tti->tti_transno != 0)) {
+		if (*transno_p > tti->tti_transno &&
+		    !tgt->lut_no_reconstruct) {
+			CERROR("%s: trying to overwrite bigger transno:"
+			       "on-disk: "LPU64", new: "LPU64" replay: %d. "
+			       "see LU-617.\n", tgt_name(tgt), *transno_p,
+			       tti->tti_transno, req_is_replay(req));
+			if (req_is_replay(req)) {
+				spin_lock(&req->rq_export->exp_lock);
+				req->rq_export->exp_vbr_failed = 1;
+				spin_unlock(&req->rq_export->exp_lock);
+			}
+			mutex_unlock(&ted->ted_lcd_lock);
+			RETURN(req_is_replay(req) ? -EOVERFLOW : 0);
+		}
+		*transno_p = tti->tti_transno;
+	}
+
+	if (!lw_client) {
+		tti->tti_off = ted->ted_lr_off;
+		rc = tgt_client_data_write(env, tgt, ted->ted_lcd, &tti->tti_off, th);
+		if (rc < 0) {
+			mutex_unlock(&ted->ted_lcd_lock);
+			RETURN(rc);
+		}
+	}
+	mutex_unlock(&ted->ted_lcd_lock);
+	EXIT;
+srv_update:
+	if (update)
+		rc = tgt_server_data_write(env, tgt, th);
+	return rc;
+}
+
+/*
+ * last_rcvd update for echo client simulation.
+ * It updates last_rcvd client slot and version of object in
+ * simple way but with all locks to simulate all drawbacks
+ */
+static int tgt_last_rcvd_update_echo(const struct lu_env *env,
+				     struct lu_target *tgt,
+				     struct dt_object *obj,
+				     struct thandle *th,
+				     struct obd_export *exp)
+{
+	struct tgt_thread_info	*tti = tgt_th_info(env);
+	struct tg_export_data	*ted = &exp->exp_target_data;
+	int			 rc = 0;
+
+	ENTRY;
+
+	tti->tti_transno = 0;
+
+	spin_lock(&tgt->lut_translock);
+	if (th->th_result == 0)
+		tti->tti_transno = ++tgt->lut_last_transno;
+	spin_unlock(&tgt->lut_translock);
+
+	/** VBR: set new versions */
+	if (th->th_result == 0 && obj != NULL)
+		dt_version_set(env, obj, tti->tti_transno, th);
+
+	/* if can't add callback, do sync write */
+	th->th_sync |= !!tgt_last_commit_cb_add(th, tgt, exp,
+						tti->tti_transno);
+
+	LASSERT(ted->ted_lr_off > 0);
+
+	mutex_lock(&ted->ted_lcd_lock);
+	LASSERT(ergo(tti->tti_transno == 0, th->th_result != 0));
+	ted->ted_lcd->lcd_last_transno = tti->tti_transno;
+	ted->ted_lcd->lcd_last_result = th->th_result;
+
+	tti->tti_off = ted->ted_lr_off;
+	rc = tgt_client_data_write(env, tgt, ted->ted_lcd, &tti->tti_off, th);
+	mutex_unlock(&ted->ted_lcd_lock);
+	RETURN(rc);
+}
+
+static int tgt_clients_data_init(const struct lu_env *env,
+				 struct lu_target *tgt,
+				 unsigned long last_size)
+{
+	struct obd_device	*obd = tgt->lut_obd;
+	struct lr_server_data	*lsd = &tgt->lut_lsd;
+	struct lsd_client_data	*lcd = NULL;
+	struct tg_export_data	*ted;
+	int			 cl_idx;
+	int			 rc = 0;
+	loff_t			 off = lsd->lsd_client_start;
+
+	ENTRY;
+
+	CLASSERT(offsetof(struct lsd_client_data, lcd_padding) +
+		 sizeof(lcd->lcd_padding) == LR_CLIENT_SIZE);
+
+	OBD_ALLOC_PTR(lcd);
+	if (lcd == NULL)
+		RETURN(-ENOMEM);
+
+	for (cl_idx = 0; off < last_size; cl_idx++) {
+		struct obd_export	*exp;
+		__u64			 last_transno;
+
+		/* Don't assume off is incremented properly by
+		 * read_record(), in case sizeof(*lcd)
+		 * isn't the same as fsd->lsd_client_size.  */
+		off = lsd->lsd_client_start + cl_idx * lsd->lsd_client_size;
+		rc = tgt_client_data_read(env, tgt, lcd, &off, cl_idx);
+		if (rc) {
+			CERROR("%s: error reading last_rcvd %s idx %d off "
+			       "%llu: rc = %d\n", tgt_name(tgt), LAST_RCVD,
+			       cl_idx, off, rc);
+			rc = 0;
+			break; /* read error shouldn't cause startup to fail */
+		}
+
+		if (lcd->lcd_uuid[0] == '\0') {
+			CDEBUG(D_INFO, "skipping zeroed client at offset %d\n",
+			       cl_idx);
+			continue;
+		}
+
+		last_transno = lcd_last_transno(lcd);
+
+		/* These exports are cleaned up by disconnect, so they
+		 * need to be set up like real exports as connect does.
+		 */
+		CDEBUG(D_HA, "RCVRNG CLIENT uuid: %s idx: %d lr: "LPU64
+		       " srv lr: "LPU64" lx: "LPU64"\n", lcd->lcd_uuid, cl_idx,
+		       last_transno, lsd->lsd_last_transno, lcd_last_xid(lcd));
+
+		exp = class_new_export(obd, (struct obd_uuid *)lcd->lcd_uuid);
+		if (IS_ERR(exp)) {
+			if (PTR_ERR(exp) == -EALREADY) {
+				/* export already exists, zero out this one */
+				CERROR("%s: Duplicate export %s!\n",
+				       tgt_name(tgt), lcd->lcd_uuid);
+				continue;
+			}
+			GOTO(err_out, rc = PTR_ERR(exp));
+		}
+
+		ted = &exp->exp_target_data;
+		*ted->ted_lcd = *lcd;
+
+		rc = tgt_client_add(env, exp, cl_idx);
+		LASSERTF(rc == 0, "rc = %d\n", rc); /* can't fail existing */
+		/* VBR: set export last committed version */
+		exp->exp_last_committed = last_transno;
+		spin_lock(&exp->exp_lock);
+		exp->exp_connecting = 0;
+		exp->exp_in_recovery = 0;
+		spin_unlock(&exp->exp_lock);
+		obd->obd_max_recoverable_clients++;
+		class_export_put(exp);
+
+		/* Need to check last_rcvd even for duplicated exports. */
+		CDEBUG(D_OTHER, "client at idx %d has last_transno = "LPU64"\n",
+		       cl_idx, last_transno);
+
+		spin_lock(&tgt->lut_translock);
+		tgt->lut_last_transno = max(last_transno,
+					    tgt->lut_last_transno);
+		spin_unlock(&tgt->lut_translock);
+	}
+
+err_out:
+	OBD_FREE_PTR(lcd);
+	RETURN(rc);
+}
+
+struct server_compat_data {
+	__u32 rocompat;
+	__u32 incompat;
+	__u32 rocinit;
+	__u32 incinit;
+};
+
+static struct server_compat_data tgt_scd[] = {
+	[LDD_F_SV_TYPE_MDT] = {
+		.rocompat = OBD_ROCOMPAT_LOVOBJID,
+		.incompat = OBD_INCOMPAT_MDT | OBD_INCOMPAT_COMMON_LR |
+			    OBD_INCOMPAT_FID | OBD_INCOMPAT_IAM_DIR |
+			    OBD_INCOMPAT_LMM_VER | OBD_INCOMPAT_MULTI_OI,
+		.rocinit = OBD_ROCOMPAT_LOVOBJID,
+		.incinit = OBD_INCOMPAT_MDT | OBD_INCOMPAT_COMMON_LR |
+			   OBD_INCOMPAT_MULTI_OI,
+	},
+	[LDD_F_SV_TYPE_OST] = {
+		.rocompat = OBD_ROCOMPAT_IDX_IN_IDIF,
+		.incompat = OBD_INCOMPAT_OST | OBD_INCOMPAT_COMMON_LR |
+			    OBD_INCOMPAT_FID,
+		.rocinit = OBD_ROCOMPAT_IDX_IN_IDIF,
+		.incinit = OBD_INCOMPAT_OST | OBD_INCOMPAT_COMMON_LR,
+	}
+};
+
+int tgt_server_data_init(const struct lu_env *env, struct lu_target *tgt)
+{
+	struct tgt_thread_info		*tti = tgt_th_info(env);
+	struct lr_server_data		*lsd = &tgt->lut_lsd;
+	unsigned long			 last_rcvd_size;
+	__u32				 index;
+	int				 rc, type;
+
+	rc = dt_attr_get(env, tgt->lut_last_rcvd, &tti->tti_attr, BYPASS_CAPA);
+	if (rc)
+		RETURN(rc);
+
+	last_rcvd_size = (unsigned long)tti->tti_attr.la_size;
+
+	/* ensure padding in the struct is the correct size */
+	CLASSERT(offsetof(struct lr_server_data, lsd_padding) +
+		 sizeof(lsd->lsd_padding) == LR_SERVER_SIZE);
+
+	rc = server_name2index(tgt_name(tgt), &index, NULL);
+	if (rc < 0) {
+		CERROR("%s: Can not get index from name: rc = %d\n",
+		       tgt_name(tgt), rc);
+		RETURN(rc);
+	}
+	/* server_name2index() returns type */
+	type = rc;
+	if (type != LDD_F_SV_TYPE_MDT && type != LDD_F_SV_TYPE_OST) {
+		CERROR("%s: unknown target type %x\n", tgt_name(tgt), type);
+		RETURN(-EINVAL);
+	}
+
+	/* last_rcvd on OST doesn't provide reconstruct support because there
+	 * may be up to 8 in-flight write requests per single slot in
+	 * last_rcvd client data
+	 */
+	tgt->lut_no_reconstruct = (type == LDD_F_SV_TYPE_OST);
+
+	if (last_rcvd_size == 0) {
+		LCONSOLE_WARN("%s: new disk, initializing\n", tgt_name(tgt));
+
+		memcpy(lsd->lsd_uuid, tgt->lut_obd->obd_uuid.uuid,
+		       sizeof(lsd->lsd_uuid));
+		lsd->lsd_last_transno = 0;
+		lsd->lsd_mount_count = 0;
+		lsd->lsd_server_size = LR_SERVER_SIZE;
+		lsd->lsd_client_start = LR_CLIENT_START;
+		lsd->lsd_client_size = LR_CLIENT_SIZE;
+		lsd->lsd_subdir_count = OBJ_SUBDIR_COUNT;
+		lsd->lsd_osd_index = index;
+		lsd->lsd_feature_rocompat = tgt_scd[type].rocinit;
+		lsd->lsd_feature_incompat = tgt_scd[type].incinit;
+	} else {
+		rc = tgt_server_data_read(env, tgt);
+		if (rc) {
+			CERROR("%s: error reading LAST_RCVD: rc= %d\n",
+			       tgt_name(tgt), rc);
+			RETURN(rc);
+		}
+		if (strcmp(lsd->lsd_uuid, tgt->lut_obd->obd_uuid.uuid)) {
+			LCONSOLE_ERROR_MSG(0x157, "Trying to start OBD %s "
+					   "using the wrong disk %s. Were the"
+					   " /dev/ assignments rearranged?\n",
+					   tgt->lut_obd->obd_uuid.uuid,
+					   lsd->lsd_uuid);
+			RETURN(-EINVAL);
+		}
+
+		if (lsd->lsd_osd_index != index) {
+			LCONSOLE_ERROR_MSG(0x157, "%s: index %d in last rcvd "
+					   "is different with the index %d in"
+					   "config log, It might be disk"
+					   "corruption!\n", tgt_name(tgt),
+					   lsd->lsd_osd_index, index);
+			RETURN(-EINVAL);
+		}
+	}
+
+	if (lsd->lsd_feature_incompat & ~tgt_scd[type].incompat) {
+		CERROR("%s: unsupported incompat filesystem feature(s) %x\n",
+		       tgt_name(tgt),
+		       lsd->lsd_feature_incompat & ~tgt_scd[type].incompat);
+		RETURN(-EINVAL);
+	}
+
+	if (type == LDD_F_SV_TYPE_MDT)
+		lsd->lsd_feature_incompat |= OBD_INCOMPAT_FID;
+
+	if (lsd->lsd_feature_rocompat & ~tgt_scd[type].rocompat) {
+		CERROR("%s: unsupported read-only filesystem feature(s) %x\n",
+		       tgt_name(tgt),
+		       lsd->lsd_feature_rocompat & ~tgt_scd[type].rocompat);
+		RETURN(-EINVAL);
+	}
+	/** Interop: evict all clients at first boot with 1.8 last_rcvd */
+	if (type == LDD_F_SV_TYPE_MDT &&
+	    !(lsd->lsd_feature_compat & OBD_COMPAT_20)) {
+		if (last_rcvd_size > lsd->lsd_client_start) {
+			LCONSOLE_WARN("%s: mounting at first time on 1.8 FS, "
+				      "remove all clients for interop needs\n",
+				      tgt_name(tgt));
+			rc = tgt_truncate_last_rcvd(env, tgt,
+						    lsd->lsd_client_start);
+			if (rc)
+				RETURN(rc);
+			last_rcvd_size = lsd->lsd_client_start;
+		}
+		/** set 2.0 flag to upgrade/downgrade between 1.8 and 2.0 */
+		lsd->lsd_feature_compat |= OBD_COMPAT_20;
+	}
+
+	spin_lock(&tgt->lut_translock);
+	tgt->lut_last_transno = lsd->lsd_last_transno;
+	spin_unlock(&tgt->lut_translock);
+
+	lsd->lsd_mount_count++;
+
+	CDEBUG(D_INODE, "=======,=BEGIN DUMPING LAST_RCVD========\n");
+	CDEBUG(D_INODE, "%s: server last_transno: "LPU64"\n",
+	       tgt_name(tgt), tgt->lut_last_transno);
+	CDEBUG(D_INODE, "%s: server mount_count: "LPU64"\n",
+	       tgt_name(tgt), lsd->lsd_mount_count);
+	CDEBUG(D_INODE, "%s: server data size: %u\n",
+	       tgt_name(tgt), lsd->lsd_server_size);
+	CDEBUG(D_INODE, "%s: per-client data start: %u\n",
+	       tgt_name(tgt), lsd->lsd_client_start);
+	CDEBUG(D_INODE, "%s: per-client data size: %u\n",
+	       tgt_name(tgt), lsd->lsd_client_size);
+	CDEBUG(D_INODE, "%s: last_rcvd size: %lu\n",
+	       tgt_name(tgt), last_rcvd_size);
+	CDEBUG(D_INODE, "%s: server subdir_count: %u\n",
+	       tgt_name(tgt), lsd->lsd_subdir_count);
+	CDEBUG(D_INODE, "%s: last_rcvd clients: %lu\n", tgt_name(tgt),
+	       last_rcvd_size <= lsd->lsd_client_start ? 0 :
+	       (last_rcvd_size - lsd->lsd_client_start) /
+		lsd->lsd_client_size);
+	CDEBUG(D_INODE, "========END DUMPING LAST_RCVD========\n");
+
+	if (lsd->lsd_server_size == 0 || lsd->lsd_client_start == 0 ||
+	    lsd->lsd_client_size == 0) {
+		CERROR("%s: bad last_rcvd contents!\n", tgt_name(tgt));
+		RETURN(-EINVAL);
+	}
+
+	if (!tgt->lut_obd->obd_replayable)
+		CWARN("%s: recovery support OFF\n", tgt_name(tgt));
+
+	rc = tgt_clients_data_init(env, tgt, last_rcvd_size);
+	if (rc < 0)
+		GOTO(err_client, rc);
+
+	spin_lock(&tgt->lut_translock);
+	/* obd_last_committed is used for compatibility
+	 * with other lustre recovery code */
+	tgt->lut_obd->obd_last_committed = tgt->lut_last_transno;
+	spin_unlock(&tgt->lut_translock);
+
+	tgt->lut_obd->u.obt.obt_mount_count = lsd->lsd_mount_count;
+	tgt->lut_obd->u.obt.obt_instance = (__u32)lsd->lsd_mount_count;
+
+	/* save it, so mount count and last_transno is current */
+	rc = tgt_server_data_update(env, tgt, 0);
+	if (rc < 0)
+		GOTO(err_client, rc);
+
+	RETURN(0);
+
+err_client:
+	class_disconnect_exports(tgt->lut_obd);
+	return rc;
+}
+
+/* add credits for last_rcvd update */
+int tgt_txn_start_cb(const struct lu_env *env, struct thandle *th,
+		     void *cookie)
+{
+	struct lu_target	*tgt = cookie;
+	struct tgt_session_info	*tsi;
+	struct tgt_thread_info	*tti = tgt_th_info(env);
+	int			 rc;
+
+	/* if there is no session, then this transaction is not result of
+	 * request processing but some local operation */
+	if (env->le_ses == NULL)
+		return 0;
+
+	LASSERT(tgt->lut_last_rcvd);
+	tsi = tgt_ses_info(env);
+	/* OFD may start transaction without export assigned */
+	if (tsi->tsi_exp == NULL)
+		return 0;
+
+	tti_buf_lcd(tti);
+	rc = dt_declare_record_write(env, tgt->lut_last_rcvd,
+				     &tti->tti_buf,
+				     tsi->tsi_exp->exp_target_data.ted_lr_off,
+				     th);
+	if (rc)
+		return rc;
+
+	tti_buf_lsd(tti);
+	rc = dt_declare_record_write(env, tgt->lut_last_rcvd,
+				     &tti->tti_buf, 0, th);
+	if (rc)
+		return rc;
+
+	if (tsi->tsi_vbr_obj != NULL &&
+	    !lu_object_remote(&tsi->tsi_vbr_obj->do_lu))
+		rc = dt_declare_version_set(env, tsi->tsi_vbr_obj, th);
+
+	return rc;
+}
+
+/* Update last_rcvd records with latests transaction data */
+int tgt_txn_stop_cb(const struct lu_env *env, struct thandle *th,
+		    void *cookie)
+{
+	struct lu_target	*tgt = cookie;
+	struct tgt_session_info	*tsi;
+	struct tgt_thread_info	*tti = tgt_th_info(env);
+	struct dt_object	*obj = NULL;
+	int			 rc;
+	bool			 echo_client;
+
+	if (env->le_ses == NULL)
+		return 0;
+
+	tsi = tgt_ses_info(env);
+	/* OFD may start transaction without export assigned */
+	if (tsi->tsi_exp == NULL)
+		return 0;
+
+	echo_client = (tgt_ses_req(tsi) == NULL);
+
+	if (tti->tti_has_trans && !echo_client) {
+		if (tti->tti_mult_trans == 0) {
+			CDEBUG(D_HA, "More than one transaction "LPU64"\n",
+			       tti->tti_transno);
+			RETURN(0);
+		}
+		/* we need another transno to be assigned */
+		tti->tti_transno = 0;
+	} else if (th->th_result == 0) {
+		tti->tti_has_trans = 1;
+	}
+
+	if (tsi->tsi_vbr_obj != NULL &&
+	    !lu_object_remote(&tsi->tsi_vbr_obj->do_lu)) {
+		obj = tsi->tsi_vbr_obj;
+	}
+
+	if (unlikely(echo_client)) /* echo client special case */
+		rc = tgt_last_rcvd_update_echo(env, tgt, obj, th,
+					       tsi->tsi_exp);
+	else
+		rc = tgt_last_rcvd_update(env, tgt, obj, tsi->tsi_opdata, th,
+					  tgt_ses_req(tsi));
+	return rc;
+}