Whamcloud - gitweb
LU-3467 mdt: call MDT handlers via unified request handler
[fs/lustre-release.git] / lustre / mgs / mgs_handler.c
index 29b7ab7..1b5f2e0 100644 (file)
@@ -27,7 +27,7 @@
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2012, Whamcloud, Inc.
+ * Copyright (c) 2010, 2013, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 #define DEBUG_SUBSYSTEM S_MGS
 #define D_MGS D_CONFIG
 
-#ifdef __KERNEL__
-# include <linux/module.h>
-# include <linux/pagemap.h>
-# include <linux/miscdevice.h>
-# include <linux/init.h>
-#else
-# include <liblustre.h>
-#endif
-
 #include <obd_class.h>
-#include <lustre_dlm.h>
 #include <lprocfs_status.h>
-#include <lustre_fsfilt.h>
-#include <lustre_disk.h>
 #include <lustre_param.h>
-#include <lustre_log.h>
 
 #include "mgs_internal.h"
 
-/* Establish a connection to the MGS.*/
-static int mgs_connect(const struct lu_env *env,
-                       struct obd_export **exp, struct obd_device *obd,
-                       struct obd_uuid *cluuid, struct obd_connect_data *data,
-                       void *localdata)
+/*
+ * Regular MGS handlers
+ */
+static int mgs_connect(struct tgt_session_info *tsi)
 {
-        struct obd_export *lexp;
-        struct lustre_handle conn = { 0 };
-        int rc;
-        ENTRY;
-
-        if (!exp || !obd || !cluuid)
-                RETURN(-EINVAL);
-
-        rc = class_connect(&conn, obd, cluuid);
-        if (rc)
-                RETURN(rc);
-
-        lexp = class_conn2export(&conn);
-       if (lexp == NULL)
-               GOTO(out, rc = -EFAULT);
-
-        mgs_counter_incr(lexp, LPROC_MGS_CONNECT);
+       struct ptlrpc_request   *req = tgt_ses_req(tsi);
+       int                      rc;
 
-        if (data != NULL) {
-                data->ocd_connect_flags &= MGS_CONNECT_SUPPORTED;
-                lexp->exp_connect_flags = data->ocd_connect_flags;
-                data->ocd_version = LUSTRE_VERSION_CODE;
-        }
+       ENTRY;
 
-        rc = mgs_export_stats_init(obd, lexp, localdata);
+       rc = tgt_connect(tsi);
+       if (rc)
+               RETURN(rc);
 
-out:
-        if (rc) {
-                class_disconnect(lexp);
-        } else {
-                *exp = lexp;
-        }
+       if (lustre_msg_get_conn_cnt(req->rq_reqmsg) > 1)
+               lustre_msg_add_op_flags(req->rq_repmsg, MSG_CONNECT_RECONNECT);
 
-        RETURN(rc);
+       RETURN(0);
 }
 
-static int mgs_reconnect(const struct lu_env *env,
-                         struct obd_export *exp, struct obd_device *obd,
-                         struct obd_uuid *cluuid, struct obd_connect_data *data,
-                         void *localdata)
+static int mgs_disconnect(struct tgt_session_info *tsi)
 {
-        ENTRY;
-
-        if (exp == NULL || obd == NULL || cluuid == NULL)
-                RETURN(-EINVAL);
+       int rc;
 
-        mgs_counter_incr(exp, LPROC_MGS_CONNECT);
+       ENTRY;
 
-        if (data != NULL) {
-                data->ocd_connect_flags &= MGS_CONNECT_SUPPORTED;
-                exp->exp_connect_flags = data->ocd_connect_flags;
-                data->ocd_version = LUSTRE_VERSION_CODE;
-        }
+       LASSERT(tsi->tsi_exp);
 
-        RETURN(mgs_export_stats_init(obd, exp, localdata));
+       rc = tgt_disconnect(tsi);
+       if (rc)
+               RETURN(err_serious(rc));
+       RETURN(0);
 }
 
-static int mgs_disconnect(struct obd_export *exp)
+static int mgs_exception(struct tgt_session_info *tsi)
 {
-        int rc;
-        ENTRY;
-
-        LASSERT(exp);
-
-        mgs_fsc_cleanup(exp);
+       ENTRY;
 
-        class_export_get(exp);
-        mgs_counter_incr(exp, LPROC_MGS_DISCONNECT);
+       tgt_counter_incr(tsi->tsi_exp, LPROC_MGS_EXCEPTION);
 
-        rc = server_disconnect_export(exp);
-        class_export_put(exp);
-        RETURN(rc);
+       RETURN(0);
 }
 
-static int mgs_handle(struct ptlrpc_request *req);
-
-static int mgs_llog_init(struct obd_device *obd, struct obd_llog_group *olg,
-                        struct obd_device *tgt, int *index)
+static int mgs_set_info(struct tgt_session_info *tsi)
 {
-       int rc;
+       struct mgs_thread_info  *mgi;
+       struct mgs_send_param   *msp, *rep_msp;
+       struct lustre_cfg       *lcfg;
+       int                      rc;
 
        ENTRY;
 
-       LASSERT(olg == &obd->obd_olg);
-       rc = llog_setup(NULL, obd, olg, LLOG_CONFIG_ORIG_CTXT, obd,
-                       &llog_lvfs_ops);
-       RETURN(rc);
-}
+       mgi = mgs_env_info(tsi->tsi_env);
+       if (IS_ERR(mgi))
+               RETURN(err_serious(PTR_ERR(mgi)));
 
-static int mgs_llog_finish(struct obd_device *obd, int count)
-{
-       struct llog_ctxt *ctxt;
+       msp = req_capsule_client_get(tsi->tsi_pill, &RMF_MGS_SEND_PARAM);
+       if (msp == NULL)
+               RETURN(err_serious(-EFAULT));
 
-       ENTRY;
+       /* Construct lustre_cfg structure to pass to function mgs_setparam */
+       lustre_cfg_bufs_reset(&mgi->mgi_bufs, NULL);
+       lustre_cfg_bufs_set_string(&mgi->mgi_bufs, 1, msp->mgs_param);
+       lcfg = lustre_cfg_new(LCFG_PARAM, &mgi->mgi_bufs);
 
-       ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
-       if (ctxt)
-               llog_cleanup(NULL, ctxt);
+       rc = mgs_setparam(tsi->tsi_env, exp2mgs_dev(tsi->tsi_exp), lcfg,
+                         mgi->mgi_fsname);
+       if (rc) {
+               LCONSOLE_WARN("%s: Unable to set parameter %s for %s: %d\n",
+                             tgt_name(tsi->tsi_tgt), msp->mgs_param,
+                             mgi->mgi_fsname, rc);
+               GOTO(out_cfg, rc);
+       }
 
-       RETURN(0);
+       /* send back the whole msp in the reply */
+       rep_msp = req_capsule_server_get(tsi->tsi_pill, &RMF_MGS_SEND_PARAM);
+       *rep_msp = *msp;
+       EXIT;
+out_cfg:
+       lustre_cfg_free(lcfg);
+       return rc;
 }
 
-static int mgs_completion_ast_config(struct ldlm_lock *lock, int flags,
-                                     void *cbdata)
-{
-        ENTRY;
-
-        if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
-                       LDLM_FL_BLOCK_CONV))) {
-                struct fs_db *fsdb = (struct fs_db *)lock->l_ast_data;
-                struct lustre_handle lockh;
+enum ast_type {
+               AST_CONFIG = 1,
+               AST_PARAMS = 2,
+               AST_IR = 3
+};
 
-                /* clear the bit before lock put */
-                cfs_clear_bit(FSDB_REVOKING_LOCK, &fsdb->fsdb_flags);
+static int mgs_completion_ast_generic(struct ldlm_lock *lock, __u64 flags,
+                                    void *cbdata, enum ast_type type)
+{
+       ENTRY;
 
-                ldlm_lock2handle(lock, &lockh);
-                ldlm_lock_decref_and_cancel(&lockh, LCK_EX);
-        }
+       if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
+                      LDLM_FL_BLOCK_CONV))) {
+               struct fs_db *fsdb;
+
+               /* l_ast_data is used as a marker to avoid cancel ldlm lock
+                * twice. See LU-2317. */
+               lock_res_and_lock(lock);
+               fsdb = (struct fs_db *)lock->l_ast_data;
+               lock->l_ast_data = NULL;
+               unlock_res_and_lock(lock);
+
+               if (fsdb != NULL) {
+                       struct lustre_handle lockh;
+
+                       switch(type) {
+                               case AST_CONFIG:
+                                       /* clear the bit before lock put */
+                                       clear_bit(FSDB_REVOKING_LOCK,
+                                                 &fsdb->fsdb_flags);
+                                       break;
+                               case AST_PARAMS:
+                                       clear_bit(FSDB_REVOKING_PARAMS,
+                                                 &fsdb->fsdb_flags);
+                                       break;
+                               case AST_IR:
+                                       mgs_ir_notify_complete(fsdb);
+                                       break;
+                               default:
+                                       LBUG();
+                       }
+
+                       ldlm_lock2handle(lock, &lockh);
+                       ldlm_lock_decref_and_cancel(&lockh, LCK_EX);
+               }
+       }
 
-        RETURN(ldlm_completion_ast(lock, flags, cbdata));
+       RETURN(ldlm_completion_ast(lock, flags, cbdata));
 }
 
-static int mgs_completion_ast_ir(struct ldlm_lock *lock, int flags,
-                                 void *cbdata)
+static int mgs_completion_ast_config(struct ldlm_lock *lock, __u64 flags,
+                                    void *cbdata)
 {
-        ENTRY;
-
-        if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
-                       LDLM_FL_BLOCK_CONV))) {
-                struct fs_db *fsdb;
-
-                /* l_ast_data is used as a marker to avoid cancel ldlm lock
-                 * twice. See LU-1259. */
-                lock_res_and_lock(lock);
-                fsdb = (struct fs_db *)lock->l_ast_data;
-                lock->l_ast_data = NULL;
-                unlock_res_and_lock(lock);
-
-                if (fsdb != NULL) {
-                        struct lustre_handle lockh;
-
-                        mgs_ir_notify_complete(fsdb);
+       return mgs_completion_ast_generic(lock, flags, cbdata, AST_CONFIG);
+}
 
-                        ldlm_lock2handle(lock, &lockh);
-                        ldlm_lock_decref_and_cancel(&lockh, LCK_EX);
-                }
-        }
+static int mgs_completion_ast_params(struct ldlm_lock *lock, __u64 flags,
+                                    void *cbdata)
+{
+       return mgs_completion_ast_generic(lock, flags, cbdata, AST_PARAMS);
+}
 
-        RETURN(ldlm_completion_ast(lock, flags, cbdata));
+static int mgs_completion_ast_ir(struct ldlm_lock *lock, __u64 flags,
+                                void *cbdata)
+{
+       return mgs_completion_ast_generic(lock, flags, cbdata, AST_IR);
 }
 
 void mgs_revoke_lock(struct mgs_device *mgs, struct fs_db *fsdb, int type)
 {
-        ldlm_completion_callback cp = NULL;
-        struct lustre_handle     lockh = { 0 };
-        struct ldlm_res_id       res_id;
-        int flags = LDLM_FL_ATOMIC_CB;
-        int rc;
-        ENTRY;
-
-        LASSERT(fsdb->fsdb_name[0] != '\0');
-        rc = mgc_fsname2resid(fsdb->fsdb_name, &res_id, type);
-        LASSERT(rc == 0);
+       ldlm_completion_callback cp = NULL;
+       struct lustre_handle     lockh = { 0 };
+       struct ldlm_res_id       res_id;
+       __u64 flags = LDLM_FL_ATOMIC_CB;
+       int rc;
+       ENTRY;
 
-        switch (type) {
-        case CONFIG_T_CONFIG:
-                cp = mgs_completion_ast_config;
-                if (cfs_test_and_set_bit(FSDB_REVOKING_LOCK, &fsdb->fsdb_flags))
-                        rc = -EALREADY;
-                break;
-        case CONFIG_T_RECOVER:
-                cp = mgs_completion_ast_ir;
-        default:
-                break;
-        }
+       LASSERT(fsdb->fsdb_name[0] != '\0');
+       rc = mgc_fsname2resid(fsdb->fsdb_name, &res_id, type);
+       LASSERT(rc == 0);
+       switch (type) {
+       case CONFIG_T_CONFIG:
+               cp = mgs_completion_ast_config;
+               if (test_and_set_bit(FSDB_REVOKING_LOCK, &fsdb->fsdb_flags))
+                       rc = -EALREADY;
+               break;
+       case CONFIG_T_PARAMS:
+               cp = mgs_completion_ast_params;
+               if (test_and_set_bit(FSDB_REVOKING_PARAMS, &fsdb->fsdb_flags))
+                       rc = -EALREADY;
+               break;
+       case CONFIG_T_RECOVER:
+               cp = mgs_completion_ast_ir;
+       default:
+               break;
+       }
 
-        if (!rc) {
-                LASSERT(cp != NULL);
+       if (!rc) {
+               LASSERT(cp != NULL);
                rc = ldlm_cli_enqueue_local(mgs->mgs_obd->obd_namespace,
                                            &res_id, LDLM_PLAIN, NULL, LCK_EX,
                                            &flags, ldlm_blocking_ast, cp,
-                                           NULL, fsdb, 0, NULL, &lockh);
-                if (rc != ELDLM_OK) {
-                        CERROR("can't take cfg lock for "LPX64"/"LPX64"(%d)\n",
-                               le64_to_cpu(res_id.name[0]),
-                               le64_to_cpu(res_id.name[1]), rc);
-
-                        if (type == CONFIG_T_CONFIG)
-                                cfs_clear_bit(FSDB_REVOKING_LOCK,
-                                              &fsdb->fsdb_flags);
-                }
-                /* lock has been cancelled in completion_ast. */
-        }
+                                           NULL, fsdb, 0, LVB_T_NONE, NULL,
+                                           &lockh);
+               if (rc != ELDLM_OK) {
+                       CERROR("can't take cfg lock for "LPX64"/"LPX64"(%d)\n",
+                              le64_to_cpu(res_id.name[0]),
+                              le64_to_cpu(res_id.name[1]), rc);
+
+                       if (type == CONFIG_T_CONFIG)
+                               clear_bit(FSDB_REVOKING_LOCK,
+                                         &fsdb->fsdb_flags);
+
+                       if (type == CONFIG_T_PARAMS)
+                               clear_bit(FSDB_REVOKING_PARAMS,
+                                         &fsdb->fsdb_flags);
+               }
+               /* lock has been cancelled in completion_ast. */
+       }
 
-        RETURN_EXIT;
+       RETURN_EXIT;
 }
 
 /* rc=0 means ok
@@ -323,26 +313,39 @@ static int mgs_check_failover_reg(struct mgs_target_info *mti)
 }
 
 /* Called whenever a target starts up.  Flags indicate first connect, etc. */
-static int mgs_handle_target_reg(struct ptlrpc_request *req)
+static int mgs_target_reg(struct tgt_session_info *tsi)
 {
-        struct obd_device *obd = req->rq_export->exp_obd;
-       struct mgs_device *mgs = exp2mgs_dev(req->rq_export);
-       struct lu_env     *env = req->rq_svc_thread->t_env;
-        struct mgs_target_info *mti, *rep_mti;
-        struct fs_db *fsdb;
-        int opc;
-        int rc = 0;
-        ENTRY;
+       struct obd_device       *obd = tsi->tsi_exp->exp_obd;
+       struct mgs_device       *mgs = exp2mgs_dev(tsi->tsi_exp);
+       struct mgs_target_info  *mti, *rep_mti;
+       struct fs_db            *fsdb;
+       int                      opc;
+       int                      rc = 0;
+
+       ENTRY;
+
+       rc = lu_env_refill((struct lu_env *)tsi->tsi_env);
+       if (rc)
+               return err_serious(rc);
 
-        mgs_counter_incr(req->rq_export, LPROC_MGS_TARGET_REG);
+       tgt_counter_incr(tsi->tsi_exp, LPROC_MGS_TARGET_REG);
 
-        mti = req_capsule_client_get(&req->rq_pill, &RMF_MGS_TARGET_INFO);
+       mti = req_capsule_client_get(tsi->tsi_pill, &RMF_MGS_TARGET_INFO);
+       if (mti == NULL) {
+               DEBUG_REQ(D_HA, tgt_ses_req(tsi), "no mgs_send_param");
+               RETURN(err_serious(-EFAULT));
+       }
+
+       if (OCD_HAS_FLAG(&tgt_ses_req(tsi)->rq_export->exp_connect_data,
+                        IMP_RECOV))
+               opc = mti->mti_flags & LDD_F_OPC_MASK;
+       else
+               opc = LDD_F_OPC_REG;
 
-        opc = mti->mti_flags & LDD_F_OPC_MASK;
         if (opc == LDD_F_OPC_READY) {
                 CDEBUG(D_MGS, "fs: %s index: %d is ready to reconnect.\n",
                        mti->mti_fsname, mti->mti_stripe_index);
-               rc = mgs_ir_update(env, mgs, mti);
+               rc = mgs_ir_update(tsi->tsi_env, mgs, mti);
                 if (rc) {
                         LASSERT(!(mti->mti_flags & LDD_F_IR_CAPABLE));
                         CERROR("Update IR return with %d(ignore and IR "
@@ -365,16 +368,16 @@ static int mgs_handle_target_reg(struct ptlrpc_request *req)
                                 LDD_F_UPDATE))) {
                 /* We're just here as a startup ping. */
                 CDEBUG(D_MGS, "Server %s is running on %s\n",
-                       mti->mti_svname, obd_export_nid2str(req->rq_export));
-               rc = mgs_check_target(env, mgs, mti);
+                      mti->mti_svname, obd_export_nid2str(tsi->tsi_exp));
+               rc = mgs_check_target(tsi->tsi_env, mgs, mti);
                 /* above will set appropriate mti flags */
                 if (rc <= 0)
                         /* Nothing wrong, or fatal error */
                         GOTO(out_nolock, rc);
-        } else {
-                if (!(mti->mti_flags & LDD_F_NO_PRIMNODE)
-                    && (rc = mgs_check_failover_reg(mti)))
-                        GOTO(out_nolock, rc);
+       } else if (!(mti->mti_flags & LDD_F_NO_PRIMNODE)) {
+               rc = mgs_check_failover_reg(mti);
+               if (rc)
+                       GOTO(out_nolock, rc);
         }
 
         OBD_FAIL_TIMEOUT(OBD_FAIL_MGS_PAUSE_TARGET_REG, 10);
@@ -382,14 +385,15 @@ static int mgs_handle_target_reg(struct ptlrpc_request *req)
         if (mti->mti_flags & LDD_F_WRITECONF) {
                 if (mti->mti_flags & LDD_F_SV_TYPE_MDT &&
                     mti->mti_stripe_index == 0) {
-                       rc = mgs_erase_logs(env, mgs, mti->mti_fsname);
+                       rc = mgs_erase_logs(tsi->tsi_env, mgs,
+                                           mti->mti_fsname);
                         LCONSOLE_WARN("%s: Logs for fs %s were removed by user "
                                       "request.  All servers must be restarted "
                                       "in order to regenerate the logs."
                                       "\n", obd->obd_name, mti->mti_fsname);
                 } else if (mti->mti_flags &
                            (LDD_F_SV_TYPE_OST | LDD_F_SV_TYPE_MDT)) {
-                       rc = mgs_erase_log(env, mgs, mti->mti_svname);
+                       rc = mgs_erase_log(tsi->tsi_env, mgs, mti->mti_svname);
                         LCONSOLE_WARN("%s: Regenerating %s log by user "
                                       "request.\n",
                                       obd->obd_name, mti->mti_svname);
@@ -401,7 +405,7 @@ static int mgs_handle_target_reg(struct ptlrpc_request *req)
                        GOTO(out_nolock, rc);
         }
 
-       rc = mgs_find_or_make_fsdb(env, mgs, mti->mti_fsname, &fsdb);
+       rc = mgs_find_or_make_fsdb(tsi->tsi_env, mgs, mti->mti_fsname, &fsdb);
         if (rc) {
                 CERROR("Can't get db for %s: %d\n", mti->mti_fsname, rc);
                 GOTO(out_nolock, rc);
@@ -426,7 +430,7 @@ static int mgs_handle_target_reg(struct ptlrpc_request *req)
 
                 /* create or update the target log
                    and update the client/mdt logs */
-               rc = mgs_write_log_target(env, mgs, mti, fsdb);
+               rc = mgs_write_log_target(tsi->tsi_env, mgs, mti, fsdb);
                 if (rc) {
                         CERROR("Failed to write %s log (%d)\n",
                                mti->mti_svname, rc);
@@ -443,362 +447,137 @@ out:
        mgs_revoke_lock(mgs, fsdb, CONFIG_T_CONFIG);
 
 out_nolock:
-        CDEBUG(D_MGS, "replying with %s, index=%d, rc=%d\n", mti->mti_svname,
-               mti->mti_stripe_index, rc);
-        req->rq_status = rc;
-        if (rc)
-                /* we need an error flag to tell the target what's going on,
-                 * instead of just doing it by error code only. */
-                mti->mti_flags |= LDD_F_ERROR;
-
-        rc = req_capsule_server_pack(&req->rq_pill);
-        if (rc)
-                RETURN(rc);
-
-        /* send back the whole mti in the reply */
-        rep_mti = req_capsule_server_get(&req->rq_pill, &RMF_MGS_TARGET_INFO);
-        *rep_mti = *mti;
-
-        /* Flush logs to disk */
-       dt_sync(req->rq_svc_thread->t_env, mgs->mgs_bottom);
-        RETURN(rc);
-}
-
-static int mgs_set_info_rpc(struct ptlrpc_request *req)
-{
-       struct mgs_device *mgs = exp2mgs_dev(req->rq_export);
-       struct lu_env     *env = req->rq_svc_thread->t_env;
-        struct mgs_send_param *msp, *rep_msp;
-       struct mgs_thread_info *mgi = mgs_env_info(env);
-        int rc;
-        struct lustre_cfg *lcfg;
-        ENTRY;
-
-        msp = req_capsule_client_get(&req->rq_pill, &RMF_MGS_SEND_PARAM);
-        LASSERT(msp);
-
-        /* Construct lustre_cfg structure to pass to function mgs_setparam */
-       lustre_cfg_bufs_reset(&mgi->mgi_bufs, NULL);
-       lustre_cfg_bufs_set_string(&mgi->mgi_bufs, 1, msp->mgs_param);
-       lcfg = lustre_cfg_new(LCFG_PARAM, &mgi->mgi_bufs);
-       if (IS_ERR(lcfg))
-               GOTO(out, rc = PTR_ERR(lcfg));
-       rc = mgs_setparam(env, mgs, lcfg, mgi->mgi_fsname);
-        if (rc) {
-                CERROR("Error %d in setting the parameter %s for fs %s\n",
-                      rc, msp->mgs_param, mgi->mgi_fsname);
-               GOTO(out_cfg, rc);
-        }
-
-        rc = req_capsule_server_pack(&req->rq_pill);
-        if (rc == 0) {
-                rep_msp = req_capsule_server_get(&req->rq_pill, &RMF_MGS_SEND_PARAM);
-                rep_msp = msp;
-        }
-out_cfg:
-       lustre_cfg_free(lcfg);
-out:
-        RETURN(rc);
-}
-
-static int mgs_config_read(struct ptlrpc_request *req)
-{
-        struct mgs_config_body *body;
-        int rc;
-        ENTRY;
-
-        body = req_capsule_client_get(&req->rq_pill, &RMF_MGS_CONFIG_BODY);
-        if (body == NULL)
-                RETURN(-EINVAL);
-
-        switch (body->mcb_type) {
-        case CONFIG_T_RECOVER:
-                rc = mgs_get_ir_logs(req);
-                break;
-
-        case CONFIG_T_CONFIG:
-                rc = -ENOTSUPP;
-                break;
-
-        default:
-                rc = -EINVAL;
-                break;
-        }
-
-        RETURN(rc);
-}
-
-/*
- * similar as in ost_connect_check_sptlrpc()
- */
-static int mgs_connect_check_sptlrpc(struct ptlrpc_request *req)
-{
-        struct obd_export     *exp = req->rq_export;
-       struct mgs_device     *mgs = exp2mgs_dev(req->rq_export);
-       struct lu_env         *env = req->rq_svc_thread->t_env;
-        struct fs_db          *fsdb;
-        struct sptlrpc_flavor  flvr;
-        int                    rc = 0;
-
-        if (exp->exp_flvr.sf_rpc == SPTLRPC_FLVR_INVALID) {
-               rc = mgs_find_or_make_fsdb(env, mgs, MGSSELF_NAME, &fsdb);
-                if (rc)
-                        return rc;
-
-                cfs_mutex_lock(&fsdb->fsdb_mutex);
-                if (sptlrpc_rule_set_choose(&fsdb->fsdb_srpc_gen,
-                                            LUSTRE_SP_MGC, LUSTRE_SP_MGS,
-                                            req->rq_peer.nid,
-                                            &flvr) == 0) {
-                        /* by defualt allow any flavors */
-                        flvr.sf_rpc = SPTLRPC_FLVR_ANY;
-                }
-                cfs_mutex_unlock(&fsdb->fsdb_mutex);
-
-                cfs_spin_lock(&exp->exp_lock);
-
-                exp->exp_sp_peer = req->rq_sp_from;
-                exp->exp_flvr = flvr;
-
-                if (exp->exp_flvr.sf_rpc != SPTLRPC_FLVR_ANY &&
-                    exp->exp_flvr.sf_rpc != req->rq_flvr.sf_rpc) {
-                        CERROR("invalid rpc flavor %x, expect %x, from %s\n",
-                               req->rq_flvr.sf_rpc, exp->exp_flvr.sf_rpc,
-                               libcfs_nid2str(req->rq_peer.nid));
-                        rc = -EACCES;
-                }
+       CDEBUG(D_MGS, "replying with %s, index=%d, rc=%d\n", mti->mti_svname,
+              mti->mti_stripe_index, rc);
+        /* An error flag is set in the mti reply rather than an error code */
+       if (rc)
+               mti->mti_flags |= LDD_F_ERROR;
 
-                cfs_spin_unlock(&exp->exp_lock);
-        } else {
-                if (exp->exp_sp_peer != req->rq_sp_from) {
-                        CERROR("RPC source %s doesn't match %s\n",
-                               sptlrpc_part2name(req->rq_sp_from),
-                               sptlrpc_part2name(exp->exp_sp_peer));
-                        rc = -EACCES;
-                } else {
-                        rc = sptlrpc_target_export_check(exp, req);
-                }
-        }
+       /* send back the whole mti in the reply */
+       rep_mti = req_capsule_server_get(tsi->tsi_pill, &RMF_MGS_TARGET_INFO);
+       *rep_mti = *mti;
 
-        return rc;
+       /* Flush logs to disk */
+       dt_sync(tsi->tsi_env, mgs->mgs_bottom);
+       RETURN(rc);
 }
 
 /* Called whenever a target cleans up. */
-/* XXX - Currently unused */
-static int mgs_handle_target_del(struct ptlrpc_request *req)
+static int mgs_target_del(struct tgt_session_info *tsi)
 {
-        ENTRY;
-        mgs_counter_incr(req->rq_export, LPROC_MGS_TARGET_DEL);
-        RETURN(0);
-}
+       ENTRY;
 
-/* XXX - Currently unused */
-static int mgs_handle_exception(struct ptlrpc_request *req)
-{
-        ENTRY;
-        mgs_counter_incr(req->rq_export, LPROC_MGS_EXCEPTION);
-        RETURN(0);
+       tgt_counter_incr(tsi->tsi_exp, LPROC_MGS_TARGET_DEL);
+
+       RETURN(0);
 }
 
-/*
- * For old clients there is no direct way of knowing which filesystems
- * a client is operating at the MGS side. But we need to pick up those
- * clients so that the MGS can mark the corresponding filesystem as
- * non-IR capable because old clients are not ready to be notified.
- *
- * This is why we have this _hack_ function. We detect the filesystem's
- * name by hacking llog operation which is currently used by the clients
- * to fetch configuration logs. At present this is fine because this is
- * the ONLY llog operation between mgc and the MGS.
- *
- * If extra llog operation is going to be added, this function needs fixing.
- *
- * If releases prior than 2.0 are not supported, we can remove this function.
- */
-static int mgs_handle_fslog_hack(struct ptlrpc_request *req)
+static int mgs_config_read(struct tgt_session_info *tsi)
 {
-        char *logname;
-        char fsname[16];
-        char *ptr;
-        int rc;
+       struct ptlrpc_request   *req = tgt_ses_req(tsi);
+       struct mgs_config_body  *body;
+       int                      rc;
 
-        /* XXX: We suppose that llog at mgs is only used for
-         * fetching file system log */
-        logname = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
-        if (logname == NULL) {
-                CERROR("No logname, is llog on MGS used for something else?\n");
-                return -EINVAL;
-        }
+       ENTRY;
 
-        ptr = strchr(logname, '-');
-        rc = (int)(ptr - logname);
-        if (ptr == NULL || rc >= sizeof(fsname)) {
-                CERROR("Invalid logname received: %s\n", logname);
-                return -EINVAL;
-        }
+       body = req_capsule_client_get(tsi->tsi_pill, &RMF_MGS_CONFIG_BODY);
+       if (body == NULL) {
+               DEBUG_REQ(D_HA, req, "no mgs_config_body");
+               RETURN(err_serious(-EFAULT));
+       }
 
-        strncpy(fsname, logname, rc);
-        fsname[rc] = 0;
-       rc = mgs_fsc_attach(req->rq_svc_thread->t_env, req->rq_export, fsname);
-        if (rc < 0 && rc != -EEXIST)
-                CERROR("add fs client %s returns %d\n", fsname, rc);
+       switch (body->mcb_type) {
+       case CONFIG_T_RECOVER:
+               rc = mgs_get_ir_logs(req);
+               break;
+       case CONFIG_T_CONFIG:
+               rc = -EOPNOTSUPP;
+               break;
+       default:
+               rc = -EINVAL;
+               break;
+       }
 
-        return rc;
+       RETURN(rc);
 }
 
-/* TODO: handle requests in a similar way as MDT: see mdt_handle_common() */
-int mgs_handle(struct ptlrpc_request *req)
+static int mgs_llog_open(struct tgt_session_info *tsi)
 {
-        int fail = OBD_FAIL_MGS_ALL_REPLY_NET;
-        int opc, rc = 0;
-        ENTRY;
-
-        req_capsule_init(&req->rq_pill, req, RCL_SERVER);
-        CFS_FAIL_TIMEOUT_MS(OBD_FAIL_MGS_PAUSE_REQ, cfs_fail_val);
-        if (CFS_FAIL_CHECK(OBD_FAIL_MGS_ALL_REQUEST_NET))
-                RETURN(0);
-
-        LASSERT(current->journal_info == NULL);
-        opc = lustre_msg_get_opc(req->rq_reqmsg);
-
-        if (opc == SEC_CTX_INIT ||
-            opc == SEC_CTX_INIT_CONT ||
-            opc == SEC_CTX_FINI)
-                GOTO(out, rc = 0);
-
-        if (opc != MGS_CONNECT) {
-                if (!class_connected_export(req->rq_export)) {
-                        DEBUG_REQ(D_MGS, req, "operation on unconnected MGS\n");
-                        req->rq_status = -ENOTCONN;
-                        GOTO(out, rc = -ENOTCONN);
-                }
-        }
-
-        switch (opc) {
-        case MGS_CONNECT:
-                DEBUG_REQ(D_MGS, req, "connect");
-                /* MGS and MDS have same request format for connect */
-                req_capsule_set(&req->rq_pill, &RQF_MDS_CONNECT);
-                rc = target_handle_connect(req);
-                if (rc == 0)
-                        rc = mgs_connect_check_sptlrpc(req);
-
-                if (!rc && (lustre_msg_get_conn_cnt(req->rq_reqmsg) > 1))
-                        /* Make clients trying to reconnect after a MGS restart
-                           happy; also requires obd_replayable */
-                        lustre_msg_add_op_flags(req->rq_repmsg,
-                                                MSG_CONNECT_RECONNECT);
-                break;
-        case MGS_DISCONNECT:
-                DEBUG_REQ(D_MGS, req, "disconnect");
-                /* MGS and MDS have same request format for disconnect */
-                req_capsule_set(&req->rq_pill, &RQF_MDS_DISCONNECT);
-                rc = target_handle_disconnect(req);
-                req->rq_status = rc;            /* superfluous? */
-                break;
-        case MGS_EXCEPTION:
-                DEBUG_REQ(D_MGS, req, "exception");
-                rc = mgs_handle_exception(req);
-                break;
-        case MGS_TARGET_REG:
-                DEBUG_REQ(D_MGS, req, "target add");
-                req_capsule_set(&req->rq_pill, &RQF_MGS_TARGET_REG);
-                rc = mgs_handle_target_reg(req);
-                break;
-        case MGS_TARGET_DEL:
-                DEBUG_REQ(D_MGS, req, "target del");
-                rc = mgs_handle_target_del(req);
-                break;
-        case MGS_SET_INFO:
-                DEBUG_REQ(D_MGS, req, "set_info");
-                req_capsule_set(&req->rq_pill, &RQF_MGS_SET_INFO);
-                rc = mgs_set_info_rpc(req);
-                break;
-        case MGS_CONFIG_READ:
-                DEBUG_REQ(D_MGS, req, "read config");
-                req_capsule_set(&req->rq_pill, &RQF_MGS_CONFIG_READ);
-                rc = mgs_config_read(req);
-                break;
-        case LDLM_ENQUEUE:
-                DEBUG_REQ(D_MGS, req, "enqueue");
-                req_capsule_set(&req->rq_pill, &RQF_LDLM_ENQUEUE);
-                rc = ldlm_handle_enqueue(req, ldlm_server_completion_ast,
-                                         ldlm_server_blocking_ast, NULL);
-                break;
-        case LDLM_BL_CALLBACK:
-        case LDLM_CP_CALLBACK:
-                DEBUG_REQ(D_MGS, req, "callback");
-                CERROR("callbacks should not happen on MGS\n");
-                LBUG();
-                break;
+       struct mgs_thread_info  *mgi;
+       struct ptlrpc_request   *req = tgt_ses_req(tsi);
+       char                    *logname;
+       int                      rc;
 
-        case OBD_PING:
-                DEBUG_REQ(D_INFO, req, "ping");
-                req_capsule_set(&req->rq_pill, &RQF_OBD_PING);
-                rc = target_handle_ping(req);
-                break;
-        case OBD_LOG_CANCEL:
-                DEBUG_REQ(D_MGS, req, "log cancel");
-                rc = -ENOTSUPP; /* la la la */
-                break;
-
-        case LLOG_ORIGIN_HANDLE_CREATE:
-               DEBUG_REQ(D_MGS, req, "llog_open");
-               req_capsule_set(&req->rq_pill, &RQF_LLOG_ORIGIN_HANDLE_CREATE);
-               rc = llog_origin_handle_open(req);
-                if (rc == 0)
-                        (void)mgs_handle_fslog_hack(req);
-                break;
-        case LLOG_ORIGIN_HANDLE_NEXT_BLOCK:
-                DEBUG_REQ(D_MGS, req, "llog next block");
-                req_capsule_set(&req->rq_pill,
-                                &RQF_LLOG_ORIGIN_HANDLE_NEXT_BLOCK);
-                rc = llog_origin_handle_next_block(req);
-                break;
-       case LLOG_ORIGIN_HANDLE_PREV_BLOCK:
-               DEBUG_REQ(D_MGS, req, "llog prev block");
-               req_capsule_set(&req->rq_pill,
-                               &RQF_LLOG_ORIGIN_HANDLE_PREV_BLOCK);
-               rc = llog_origin_handle_prev_block(req);
-               break;
-        case LLOG_ORIGIN_HANDLE_READ_HEADER:
-                DEBUG_REQ(D_MGS, req, "llog read header");
-                req_capsule_set(&req->rq_pill,
-                                &RQF_LLOG_ORIGIN_HANDLE_READ_HEADER);
-                rc = llog_origin_handle_read_header(req);
-                break;
-        case LLOG_ORIGIN_HANDLE_CLOSE:
-                DEBUG_REQ(D_MGS, req, "llog close");
-                rc = llog_origin_handle_close(req);
-                break;
-       default:
-               rc = -EOPNOTSUPP;
-        }
+       ENTRY;
 
-        LASSERT(current->journal_info == NULL);
-       if (rc) {
-               DEBUG_REQ(D_MGS, req, "MGS fail to handle opc = %d: rc = %d\n",
-                         opc, rc);
-               req->rq_status = rc;
-               rc = ptlrpc_error(req);
+       rc = tgt_llog_open(tsi);
+       if (rc)
                RETURN(rc);
+
+       /*
+        * For old clients there is no direct way of knowing which file system
+        * a client is operating at the MGS side. But we need to pick up those
+        * clients so that the MGS can mark the corresponding file system as
+        * non-IR capable because old clients are not ready to be notified.
+        *
+        * Therefore we attempt to detect the file systems name by hacking the
+        * llog operation which is currently used by the clients to fetch
+        * configuration logs. At present this is fine because this is the
+        * ONLY llog operation between mgc and the MGS.
+        *
+        * If extra llog operation are going to be added, this function needs
+        * further work.
+        *
+        * When releases prior than 2.0 are not supported, the following code
+        * can be removed.
+        */
+       mgi = mgs_env_info(tsi->tsi_env);
+       if (IS_ERR(mgi))
+               RETURN(PTR_ERR(mgi));
+
+       logname = req_capsule_client_get(tsi->tsi_pill, &RMF_NAME);
+       if (logname) {
+               char *ptr = strchr(logname, '-');
+               int   len = (int)(ptr - logname);
+
+               if (ptr == NULL || len >= sizeof(mgi->mgi_fsname)) {
+                       LCONSOLE_WARN("%s: non-config logname received: %s\n",
+                                     tgt_name(tsi->tsi_tgt), logname);
+                       /* not error, this can be llog test name */
+               } else {
+                       strncpy(mgi->mgi_fsname, logname, len);
+                       mgi->mgi_fsname[len] = 0;
+
+                       rc = mgs_fsc_attach(tsi->tsi_env, tsi->tsi_exp,
+                                           mgi->mgi_fsname);
+                       if (rc && rc != -EEXIST) {
+                               LCONSOLE_WARN("%s: Unable to add client %s "
+                                             "to file system %s: %d\n",
+                                             tgt_name(tsi->tsi_tgt),
+                                             libcfs_nid2str(req->rq_peer.nid),
+                                             mgi->mgi_fsname, rc);
+                       } else {
+                               rc = 0;
+                       }
+               }
+       } else {
+               CERROR("%s: no logname in request\n", tgt_name(tsi->tsi_tgt));
+               RETURN(-EINVAL);
        }
-out:
-        target_send_reply(req, rc, fail);
-        RETURN(0);
+       RETURN(rc);
 }
 
 static inline int mgs_init_export(struct obd_export *exp)
 {
-        struct mgs_export_data *data = &exp->u.eu_mgs_data;
+       struct mgs_export_data *data = &exp->u.eu_mgs_data;
 
-        /* init mgs_export_data for fsc */
-        cfs_spin_lock_init(&data->med_lock);
-        CFS_INIT_LIST_HEAD(&data->med_clients);
+       /* init mgs_export_data for fsc */
+       spin_lock_init(&data->med_lock);
+       CFS_INIT_LIST_HEAD(&data->med_clients);
 
-        cfs_spin_lock(&exp->exp_lock);
-        exp->exp_connecting = 1;
-        cfs_spin_unlock(&exp->exp_lock);
+       spin_lock(&exp->exp_lock);
+       exp->exp_connecting = 1;
+       spin_unlock(&exp->exp_lock);
 
         /* self-export doesn't need client data and ldlm initialization */
         if (unlikely(obd_uuid_equals(&exp->exp_obd->obd_uuid,
@@ -848,30 +627,27 @@ static int mgs_iocontrol_pool(const struct lu_env *env,
        struct mgs_thread_info *mgi = mgs_env_info(env);
         int rc;
         struct lustre_cfg *lcfg = NULL;
-        struct llog_rec_hdr rec;
         char *poolname = NULL;
         ENTRY;
 
         OBD_ALLOC(poolname, LOV_MAXPOOLNAME + 1);
        if (poolname == NULL)
                RETURN(-ENOMEM);
-        rec.lrh_len = llog_data_len(data->ioc_plen1);
 
-        if (data->ioc_type == LUSTRE_CFG_TYPE) {
-                rec.lrh_type = OBD_CFG_REC;
-        } else {
-                CERROR("unknown cfg record type:%d \n", data->ioc_type);
+       if (data->ioc_type != LUSTRE_CFG_TYPE) {
+               CERROR("%s: unknown cfg record type: %d\n",
+                      mgs->mgs_obd->obd_name, data->ioc_type);
                GOTO(out_pool, rc = -EINVAL);
         }
 
-       if (data->ioc_plen1 > CFS_PAGE_SIZE)
+       if (data->ioc_plen1 > PAGE_CACHE_SIZE)
                GOTO(out_pool, rc = -E2BIG);
 
         OBD_ALLOC(lcfg, data->ioc_plen1);
         if (lcfg == NULL)
                 GOTO(out_pool, rc = -ENOMEM);
 
-        if (cfs_copy_from_user(lcfg, data->ioc_pbuf1, data->ioc_plen1))
+       if (copy_from_user(lcfg, data->ioc_pbuf1, data->ioc_plen1))
                GOTO(out_lcfg, rc = -EFAULT);
 
        if (lcfg->lcfg_bufcount < 2)
@@ -931,7 +707,6 @@ int mgs_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
 {
        struct mgs_device *mgs = exp2mgs_dev(exp);
         struct obd_ioctl_data *data = karg;
-        struct lvfs_run_ctxt saved;
        struct lu_env env;
         int rc = 0;
 
@@ -947,21 +722,17 @@ int mgs_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
         case OBD_IOC_PARAM: {
                struct mgs_thread_info *mgi = mgs_env_info(&env);
                 struct lustre_cfg *lcfg;
-                struct llog_rec_hdr rec;
-
-                rec.lrh_len = llog_data_len(data->ioc_plen1);
 
-                if (data->ioc_type == LUSTRE_CFG_TYPE) {
-                        rec.lrh_type = OBD_CFG_REC;
-                } else {
-                        CERROR("unknown cfg record type:%d \n", data->ioc_type);
+               if (data->ioc_type != LUSTRE_CFG_TYPE) {
+                       CERROR("%s: unknown cfg record type: %d\n",
+                              mgs->mgs_obd->obd_name, data->ioc_type);
                        GOTO(out, rc = -EINVAL);
                 }
 
                 OBD_ALLOC(lcfg, data->ioc_plen1);
                 if (lcfg == NULL)
                        GOTO(out, rc = -ENOMEM);
-                if (cfs_copy_from_user(lcfg, data->ioc_pbuf1, data->ioc_plen1))
+               if (copy_from_user(lcfg, data->ioc_pbuf1, data->ioc_plen1))
                         GOTO(out_free, rc = -EFAULT);
 
                 if (lcfg->lcfg_bufcount < 1)
@@ -976,37 +747,79 @@ out_free:
                break;
         }
 
+       case OBD_IOC_REPLACE_NIDS: {
+               if (!data->ioc_inllen1 || !data->ioc_inlbuf1) {
+                       CERROR("No device name specified!\n");
+                       rc = -EINVAL;
+                       break;
+               }
+
+               if (data->ioc_inlbuf1[data->ioc_inllen1 - 1] != 0) {
+                       CERROR("Device name is not NUL terminated!\n");
+                       rc = -EINVAL;
+                       break;
+               }
+
+               if (data->ioc_plen1 > MTI_NAME_MAXLEN) {
+                       CERROR("Device name is too long\n");
+                       rc = -EOVERFLOW;
+                       break;
+               }
+
+               if (!data->ioc_inllen2 || !data->ioc_inlbuf2) {
+                       CERROR("No NIDs were specified!\n");
+                       rc = -EINVAL;
+                       break;
+               }
+
+               if (data->ioc_inlbuf2[data->ioc_inllen2 - 1] != 0) {
+                       CERROR("NID list is not NUL terminated!\n");
+                       rc = -EINVAL;
+                       break;
+               }
+
+               /* replace nids in llog */
+               rc = mgs_replace_nids(&env, mgs, data->ioc_inlbuf1,
+                                     data->ioc_inlbuf2);
+               if (rc)
+                       CERROR("%s: error replacing nids: rc = %d\n",
+                              exp->exp_obd->obd_name, rc);
+
+               break;
+       }
+
        case OBD_IOC_POOL:
                rc = mgs_iocontrol_pool(&env, mgs, data);
                break;
 
         case OBD_IOC_DUMP_LOG: {
                 struct llog_ctxt *ctxt;
+
                ctxt = llog_get_context(mgs->mgs_obd, LLOG_CONFIG_ORIG_CTXT);
-               push_ctxt(&saved, &mgs->mgs_obd->obd_lvfs_ctxt, NULL);
-                rc = class_config_dump_llog(ctxt, data->ioc_inlbuf1, NULL);
-               pop_ctxt(&saved, &mgs->mgs_obd->obd_lvfs_ctxt, NULL);
+               rc = class_config_dump_llog(&env, ctxt, data->ioc_inlbuf1,
+                                           NULL);
                 llog_ctxt_put(ctxt);
 
                break;
         }
 
+       case OBD_IOC_LLOG_CANCEL:
+       case OBD_IOC_LLOG_REMOVE:
         case OBD_IOC_LLOG_CHECK:
         case OBD_IOC_LLOG_INFO:
         case OBD_IOC_LLOG_PRINT: {
                 struct llog_ctxt *ctxt;
 
                ctxt = llog_get_context(mgs->mgs_obd, LLOG_CONFIG_ORIG_CTXT);
-               push_ctxt(&saved, &ctxt->loc_exp->exp_obd->obd_lvfs_ctxt, NULL);
-               rc = llog_ioctl(NULL, ctxt, cmd, data);
-               pop_ctxt(&saved, &ctxt->loc_exp->exp_obd->obd_lvfs_ctxt, NULL);
+               rc = llog_ioctl(&env, ctxt, cmd, data);
                llog_ctxt_put(ctxt);
                break;
         }
 
         default:
-                CDEBUG(D_INFO, "unknown command %x\n", cmd);
-               rc = -EINVAL;
+               CERROR("%s: unknown command %#x\n",
+                      mgs->mgs_obd->obd_name,  cmd);
+               rc = -ENOTTY;
                break;
         }
 out:
@@ -1048,15 +861,89 @@ out:
        RETURN(rc);
 }
 
+static struct tgt_handler mgs_mgs_handlers[] = {
+TGT_RPC_HANDLER(MGS_FIRST_OPC,
+               0,                      MGS_CONNECT,     mgs_connect,
+               &RQF_CONNECT, LUSTRE_OBD_VERSION),
+TGT_RPC_HANDLER(MGS_FIRST_OPC,
+               0,                      MGS_DISCONNECT,  mgs_disconnect,
+               &RQF_MDS_DISCONNECT, LUSTRE_OBD_VERSION),
+TGT_MGS_HDL_VAR(0,                     MGS_EXCEPTION,   mgs_exception),
+TGT_MGS_HDL    (HABEO_REFERO | MUTABOR,        MGS_SET_INFO,    mgs_set_info),
+TGT_MGS_HDL    (HABEO_REFERO | MUTABOR,        MGS_TARGET_REG,  mgs_target_reg),
+TGT_MGS_HDL_VAR(0,                     MGS_TARGET_DEL,  mgs_target_del),
+TGT_MGS_HDL    (HABEO_REFERO,          MGS_CONFIG_READ, mgs_config_read),
+};
+
+static struct tgt_handler mgs_obd_handlers[] = {
+TGT_OBD_HDL(0, OBD_PING,       tgt_obd_ping),
+};
+
+static struct tgt_handler mgs_dlm_handlers[] = {
+[LDLM_ENQUEUE - LDLM_FIRST_OPC] = {
+       .th_name = "LDLM_ENQUEUE",
+       /* don't use th_fail_id for MGS to don't interfere with MDS tests.
+        * * There are no tests for MGS with OBD_FAIL_LDLM_ENQUEUE_NET so it
+        * * is safe. If such tests will be needed we have to distinguish
+        * * MDS and MGS fail ids, e.g use OBD_FAIL_MGS_ENQUEUE_NET for MGS
+        * * instead of common OBD_FAIL_LDLM_ENQUEUE_NET */
+       .th_fail_id = 0,
+       .th_opc = LDLM_ENQUEUE,
+       .th_flags = HABEO_CLAVIS,
+       .th_act = tgt_enqueue,
+       .th_fmt = &RQF_LDLM_ENQUEUE,
+       .th_version = LUSTRE_DLM_VERSION,
+       },
+};
+
+static struct tgt_handler mgs_llog_handlers[] = {
+TGT_LLOG_HDL    (0,    LLOG_ORIGIN_HANDLE_CREATE,      mgs_llog_open),
+TGT_LLOG_HDL    (0,    LLOG_ORIGIN_HANDLE_NEXT_BLOCK,  tgt_llog_next_block),
+TGT_LLOG_HDL    (0,    LLOG_ORIGIN_HANDLE_READ_HEADER, tgt_llog_read_header),
+TGT_LLOG_HDL_VAR(0,    LLOG_ORIGIN_HANDLE_CLOSE,       tgt_llog_close),
+TGT_LLOG_HDL    (0,    LLOG_ORIGIN_HANDLE_PREV_BLOCK,  tgt_llog_prev_block),
+};
+
+static struct tgt_opc_slice mgs_common_slice[] = {
+       {
+               .tos_opc_start = MGS_FIRST_OPC,
+               .tos_opc_end   = MGS_LAST_OPC,
+               .tos_hs        = mgs_mgs_handlers
+       },
+       {
+               .tos_opc_start = OBD_FIRST_OPC,
+               .tos_opc_end   = OBD_LAST_OPC,
+               .tos_hs        = mgs_obd_handlers
+       },
+       {
+               .tos_opc_start = LDLM_FIRST_OPC,
+               .tos_opc_end   = LDLM_LAST_OPC,
+               .tos_hs        = mgs_dlm_handlers
+       },
+       {
+               .tos_opc_start = LLOG_FIRST_OPC,
+               .tos_opc_end   = LLOG_LAST_OPC,
+               .tos_hs        = mgs_llog_handlers
+       },
+       {
+               .tos_opc_start = SEC_FIRST_OPC,
+               .tos_opc_end   = SEC_LAST_OPC,
+               .tos_hs        = tgt_sec_ctx_handlers
+       },
+       {
+               .tos_hs        = NULL
+       }
+};
 
 static int mgs_init0(const struct lu_env *env, struct mgs_device *mgs,
                     struct lu_device_type *ldt, struct lustre_cfg *lcfg)
 {
-       static struct ptlrpc_service_conf       conf;
-       struct lprocfs_static_vars  lvars = { 0 };
-       struct obd_device          *obd;
-       struct lustre_mount_info   *lmi;
-       int                         rc;
+       struct ptlrpc_service_conf       conf;
+       struct obd_device               *obd;
+       struct lustre_mount_info        *lmi;
+       struct llog_ctxt                *ctxt;
+       int                              rc;
+
        ENTRY;
 
        lmi = server_get_mount(lustre_cfg_string(lcfg, 0));
@@ -1067,7 +954,7 @@ static int mgs_init0(const struct lu_env *env, struct mgs_device *mgs,
 
        rc = mgs_connect_to_osd(mgs, lustre_cfg_string(lcfg, 3));
        if (rc)
-               RETURN(rc);
+               GOTO(err_lmi, rc);
 
        obd = class_name2obd(lustre_cfg_string(lcfg, 0));
        LASSERT(obd);
@@ -1085,39 +972,50 @@ static int mgs_init0(const struct lu_env *env, struct mgs_device *mgs,
        if (obd->obd_namespace == NULL)
                GOTO(err_ops, rc = -ENOMEM);
 
-       /* ldlm setup */
-       ptlrpc_init_client(LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
-                          "mgs_ldlm_client", &obd->obd_ldlm_client);
+       /* No recovery for MGCs */
+       obd->obd_replayable = 0;
+
+       rc = tgt_init(env, &mgs->mgs_lut, obd, mgs->mgs_bottom,
+                     mgs_common_slice, OBD_FAIL_MGS_ALL_REQUEST_NET,
+                     OBD_FAIL_MGS_ALL_REPLY_NET);
+       if (rc)
+               GOTO(err_ns, rc);
 
        rc = mgs_fs_setup(env, mgs);
        if (rc) {
                CERROR("%s: MGS filesystem method init failed: rc = %d\n",
                       obd->obd_name, rc);
-               GOTO(err_ns, rc);
+               GOTO(err_tgt, rc);
        }
 
-       rc = obd_llog_init(obd, &obd->obd_olg, obd, NULL);
+       rc = llog_setup(env, obd, &obd->obd_olg, LLOG_CONFIG_ORIG_CTXT,
+                       obd, &llog_osd_ops);
        if (rc)
                GOTO(err_fs, rc);
 
-       /* No recovery for MGC's */
-       obd->obd_replayable = 0;
+       /* XXX: we need this trick till N:1 stack is supported
+        * set "current" directory for named llogs */
+       ctxt = llog_get_context(mgs->mgs_obd, LLOG_CONFIG_ORIG_CTXT);
+       LASSERT(ctxt);
+       ctxt->loc_dir = mgs->mgs_configs_dir;
+       llog_ctxt_put(ctxt);
 
        /* Internal mgs setup */
        mgs_init_fsdb_list(mgs);
-       cfs_mutex_init(&mgs->mgs_mutex);
+       mutex_init(&mgs->mgs_mutex);
        mgs->mgs_start_time = cfs_time_current_sec();
-       cfs_spin_lock_init(&mgs->mgs_lock);
+       spin_lock_init(&mgs->mgs_lock);
 
-       /* Setup proc */
-       lprocfs_mgs_init_vars(&lvars);
-       if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0) {
-               lproc_mgs_setup(mgs);
-               rc = lprocfs_alloc_md_stats(obd, LPROC_MGS_LAST);
-               if (rc)
-                       GOTO(err_llog, rc);
+       rc = lproc_mgs_setup(mgs, lustre_cfg_string(lcfg, 3));
+       if (rc != 0) {
+               CERROR("%s: cannot initialize proc entry: rc = %d\n",
+                      obd->obd_name, rc);
+               GOTO(err_llog, rc);
        }
 
+       ptlrpc_init_client(LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
+                          "mgs_ldlm_client", &obd->obd_ldlm_client);
+
        conf = (typeof(conf)) {
                .psc_name               = LUSTRE_MGS_NAME,
                .psc_watchdog_factor    = MGS_SERVICE_WATCHDOG_FACTOR,
@@ -1136,15 +1034,17 @@ static int mgs_init0(const struct lu_env *env, struct mgs_device *mgs,
                        .tc_ctx_tags            = LCT_MG_THREAD,
                },
                .psc_ops                = {
-                       .so_req_handler         = mgs_handle,
+                       .so_req_handler         = tgt_request_handle,
                        .so_req_printer         = target_print_req,
                },
        };
+
        /* Start the service threads */
        mgs->mgs_service = ptlrpc_register_service(&conf, obd->obd_proc_entry);
        if (IS_ERR(mgs->mgs_service)) {
                rc = PTR_ERR(mgs->mgs_service);
-               CERROR("failed to start service: %d\n", rc);
+               CERROR("failed to start mgs service: %d\n", rc);
+               mgs->mgs_service = NULL;
                GOTO(err_lproc, rc);
        }
 
@@ -1155,10 +1055,16 @@ static int mgs_init0(const struct lu_env *env, struct mgs_device *mgs,
        /* device stack is not yet fully setup to keep no objects behind */
        lu_site_purge(env, mgs2lu_dev(mgs)->ld_site, ~0);
        RETURN(0);
-
 err_lproc:
        lproc_mgs_cleanup(mgs);
 err_llog:
+       ctxt = llog_get_context(mgs->mgs_obd, LLOG_CONFIG_ORIG_CTXT);
+       if (ctxt) {
+               ctxt->loc_dir = NULL;
+               llog_cleanup(env, ctxt);
+       }
+err_tgt:
+       tgt_fini(env, &mgs->mgs_lut);
 err_fs:
        /* No extra cleanup needed for llog_init_commit_thread() */
        mgs_fs_cleanup(env, mgs);
@@ -1173,6 +1079,9 @@ err_ops:
                                lu_cdebug_printer);
        }
        obd_disconnect(mgs->mgs_bottom_exp);
+err_lmi:
+       if (lmi)
+               server_put_mount(lustre_cfg_string(lcfg, 0), lmi->lmi_mnt);
        RETURN(rc);
 }
 
@@ -1302,12 +1211,16 @@ static struct lu_device *mgs_device_alloc(const struct lu_env *env,
 static struct lu_device *mgs_device_fini(const struct lu_env *env,
                                         struct lu_device *d)
 {
-       struct mgs_device *mgs = lu2mgs_dev(d);
-       struct obd_device *obd = mgs->mgs_obd;
+       struct mgs_device       *mgs = lu2mgs_dev(d);
+       struct obd_device       *obd = mgs->mgs_obd;
+       struct llog_ctxt        *ctxt;
+
        ENTRY;
 
        LASSERT(mgs->mgs_bottom);
 
+       class_disconnect_exports(obd);
+
        ping_evictor_stop();
 
        ptlrpc_unregister_service(mgs->mgs_service);
@@ -1315,10 +1228,15 @@ static struct lu_device *mgs_device_fini(const struct lu_env *env,
        obd_exports_barrier(obd);
        obd_zombie_barrier();
 
+       tgt_fini(env, &mgs->mgs_lut);
        mgs_cleanup_fsdb_list(mgs);
        lproc_mgs_cleanup(mgs);
 
-       obd_llog_finish(obd, 0);
+       ctxt = llog_get_context(mgs->mgs_obd, LLOG_CONFIG_ORIG_CTXT);
+       if (ctxt) {
+               ctxt->loc_dir = NULL;
+               llog_cleanup(env, ctxt);
+       }
 
        mgs_fs_cleanup(env, mgs);
 
@@ -1366,26 +1284,99 @@ static struct lu_device_type mgs_device_type = {
        .ldt_ctx_tags   = LCT_MG_THREAD
 };
 
+static int mgs_obd_connect(const struct lu_env *env, struct obd_export **exp,
+                          struct obd_device *obd, struct obd_uuid *cluuid,
+                          struct obd_connect_data *data, void *localdata)
+{
+       struct obd_export       *lexp;
+       struct lustre_handle     conn = { 0 };
+       int                      rc;
+
+       ENTRY;
+
+       if (exp == NULL || obd == NULL || cluuid == NULL)
+               RETURN(-EINVAL);
+
+       rc = class_connect(&conn, obd, cluuid);
+       if (rc)
+               RETURN(rc);
+
+       lexp = class_conn2export(&conn);
+       if (lexp == NULL)
+               RETURN(-EFAULT);
+
+       if (data != NULL) {
+               data->ocd_connect_flags &= MGS_CONNECT_SUPPORTED;
+               data->ocd_version = LUSTRE_VERSION_CODE;
+               lexp->exp_connect_data = *data;
+       }
+
+       tgt_counter_incr(lexp, LPROC_MGS_CONNECT);
+
+       rc = mgs_export_stats_init(obd, lexp, localdata);
+       if (rc)
+               class_disconnect(lexp);
+       else
+               *exp = lexp;
+
+       RETURN(rc);
+}
+
+static int mgs_obd_reconnect(const struct lu_env *env, struct obd_export *exp,
+                            struct obd_device *obd, struct obd_uuid *cluuid,
+                            struct obd_connect_data *data, void *localdata)
+{
+       ENTRY;
+
+       if (exp == NULL || obd == NULL || cluuid == NULL)
+               RETURN(-EINVAL);
+
+       tgt_counter_incr(exp, LPROC_MGS_CONNECT);
+
+       if (data != NULL) {
+               data->ocd_connect_flags &= MGS_CONNECT_SUPPORTED;
+               data->ocd_version = LUSTRE_VERSION_CODE;
+               exp->exp_connect_data = *data;
+       }
+
+       RETURN(mgs_export_stats_init(obd, exp, localdata));
+}
+
+static int mgs_obd_disconnect(struct obd_export *exp)
+{
+       int rc;
+
+       ENTRY;
+
+       LASSERT(exp);
+
+       mgs_fsc_cleanup(exp);
+
+       class_export_get(exp);
+       tgt_counter_incr(exp, LPROC_MGS_DISCONNECT);
+
+       rc = server_disconnect_export(exp);
+       class_export_put(exp);
+       RETURN(rc);
+}
 
 /* use obd ops to offer management infrastructure */
-static struct obd_ops mgs_obd_ops = {
-        .o_owner           = THIS_MODULE,
-        .o_connect         = mgs_connect,
-        .o_reconnect       = mgs_reconnect,
-        .o_disconnect      = mgs_disconnect,
-        .o_init_export     = mgs_init_export,
-        .o_destroy_export  = mgs_destroy_export,
-        .o_iocontrol       = mgs_iocontrol,
-        .o_llog_init       = mgs_llog_init,
-        .o_llog_finish     = mgs_llog_finish
+static struct obd_ops mgs_obd_device_ops = {
+       .o_owner                = THIS_MODULE,
+       .o_connect              = mgs_obd_connect,
+       .o_reconnect            = mgs_obd_reconnect,
+       .o_disconnect           = mgs_obd_disconnect,
+       .o_init_export          = mgs_init_export,
+       .o_destroy_export       = mgs_destroy_export,
+       .o_iocontrol            = mgs_iocontrol,
 };
 
 static int __init mgs_init(void)
 {
-        struct lprocfs_static_vars lvars;
+       struct lprocfs_static_vars lvars;
 
-        lprocfs_mgs_init_vars(&lvars);
-       class_register_type(&mgs_obd_ops, NULL, lvars.module_vars,
+       lprocfs_mgs_init_vars(&lvars);
+       class_register_type(&mgs_obd_device_ops, NULL, lvars.module_vars,
                            LUSTRE_MGS_NAME, &mgs_device_type);
 
        return 0;
@@ -1393,7 +1384,7 @@ static int __init mgs_init(void)
 
 static void /*__exit*/ mgs_exit(void)
 {
-        class_unregister_type(LUSTRE_MGS_NAME);
+       class_unregister_type(LUSTRE_MGS_NAME);
 }
 
 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");