Whamcloud - gitweb
LU-8287 nodemap: don't stop config lock when target stops
[fs/lustre-release.git] / lustre / mgc / mgc_request.c
index 4ed45a0..b263c4b 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, Whamcloud, Inc.
+ * Copyright (c) 2011, 2015, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 #define DEBUG_SUBSYSTEM S_MGC
 #define D_MGC D_CONFIG /*|D_WARNING*/
 
-#ifdef __KERNEL__
-# include <linux/module.h>
-# include <linux/pagemap.h>
-# include <linux/miscdevice.h>
-# include <linux/init.h>
-#else
-# include <liblustre.h>
-#endif
+#include <linux/module.h>
+#include <linux/kthread.h>
 
-#include <obd_class.h>
-#include <lustre_dlm.h>
+#include <dt_object.h>
 #include <lprocfs_status.h>
-#include <lustre_log.h>
-#include <lustre_fsfilt.h>
+#include <lustre_dlm.h>
 #include <lustre_disk.h>
+#include <lustre_log.h>
+#include <lustre_nodemap.h>
+#include <lustre_swab.h>
+#include <obd_class.h>
+
 #include "mgc_internal.h"
 
 static int mgc_name2resid(char *name, int len, struct ldlm_res_id *res_id,
@@ -63,7 +60,7 @@ static int mgc_name2resid(char *name, int len, struct ldlm_res_id *res_id,
 {
         __u64 resname = 0;
 
-        if (len > 8) {
+       if (len > sizeof(resname)) {
                 CERROR("name too long: %s\n", name);
                 return -EINVAL;
         }
@@ -82,9 +79,11 @@ static int mgc_name2resid(char *name, int len, struct ldlm_res_id *res_id,
         case CONFIG_T_SPTLRPC:
                 resname = 0;
                 break;
-        case CONFIG_T_RECOVER:
-                resname = type;
-                break;
+       case CONFIG_T_RECOVER:
+       case CONFIG_T_PARAMS:
+       case CONFIG_T_NODEMAP:
+               resname = type;
+               break;
         default:
                 LBUG();
         }
@@ -102,62 +101,70 @@ int mgc_fsname2resid(char *fsname, struct ldlm_res_id *res_id, int type)
 }
 EXPORT_SYMBOL(mgc_fsname2resid);
 
-int mgc_logname2resid(char *logname, struct ldlm_res_id *res_id, int type)
+static int mgc_logname2resid(char *logname, struct ldlm_res_id *res_id,
+                            int type)
 {
-        char *name_end;
-        int len;
-
-        /* logname consists of "fsname-nodetype".
-         * e.g. "lustre-MDT0001", "SUN-000-client" */
-        name_end = strrchr(logname, '-');
-        LASSERT(name_end);
-        len = name_end - logname;
-        return mgc_name2resid(logname, len, res_id, type);
+       char *name_end;
+       int len;
+
+       /* logname consists of "fsname-nodetype".
+        * e.g. "lustre-MDT0001", "SUN-000-client"
+        * there is an exception: llog "params" */
+       name_end = strrchr(logname, '-');
+       if (!name_end)
+               len = strlen(logname);
+       else
+               len = name_end - logname;
+       return mgc_name2resid(logname, len, res_id, type);
 }
 
 /********************** config llog list **********************/
-static CFS_LIST_HEAD(config_llog_list);
+static struct list_head config_llog_list = LIST_HEAD_INIT(config_llog_list);
 static DEFINE_SPINLOCK(config_list_lock);
 
 /* Take a reference to a config log */
 static int config_log_get(struct config_llog_data *cld)
 {
-        ENTRY;
-        cfs_atomic_inc(&cld->cld_refcount);
-        CDEBUG(D_INFO, "log %s refs %d\n", cld->cld_logname,
-               cfs_atomic_read(&cld->cld_refcount));
-        RETURN(0);
+       ENTRY;
+       atomic_inc(&cld->cld_refcount);
+       CDEBUG(D_INFO, "log %s refs %d\n", cld->cld_logname,
+               atomic_read(&cld->cld_refcount));
+       RETURN(0);
 }
 
 /* Drop a reference to a config log.  When no longer referenced,
    we can free the config log data */
 static void config_log_put(struct config_llog_data *cld)
 {
-        ENTRY;
-
-        CDEBUG(D_INFO, "log %s refs %d\n", cld->cld_logname,
-               cfs_atomic_read(&cld->cld_refcount));
-        LASSERT(cfs_atomic_read(&cld->cld_refcount) > 0);
-
-        /* spinlock to make sure no item with 0 refcount in the list */
-        if (cfs_atomic_dec_and_lock(&cld->cld_refcount, &config_list_lock)) {
-                cfs_list_del(&cld->cld_list_chain);
-                cfs_spin_unlock(&config_list_lock);
-
-                CDEBUG(D_MGC, "dropping config log %s\n", cld->cld_logname);
-
-                if (cld->cld_recover)
-                        config_log_put(cld->cld_recover);
-                if (cld->cld_sptlrpc)
-                        config_log_put(cld->cld_sptlrpc);
-                if (cld_is_sptlrpc(cld))
-                        sptlrpc_conf_log_stop(cld->cld_logname);
-
-                class_export_put(cld->cld_mgcexp);
-                OBD_FREE(cld, sizeof(*cld) + strlen(cld->cld_logname) + 1);
-        }
+       ENTRY;
+
+       CDEBUG(D_INFO, "log %s refs %d\n", cld->cld_logname,
+               atomic_read(&cld->cld_refcount));
+       LASSERT(atomic_read(&cld->cld_refcount) > 0);
+
+       /* spinlock to make sure no item with 0 refcount in the list */
+       if (atomic_dec_and_lock(&cld->cld_refcount, &config_list_lock)) {
+               list_del(&cld->cld_list_chain);
+               spin_unlock(&config_list_lock);
+
+               CDEBUG(D_MGC, "dropping config log %s\n", cld->cld_logname);
+
+               if (cld->cld_recover)
+                       config_log_put(cld->cld_recover);
+               if (cld->cld_sptlrpc)
+                       config_log_put(cld->cld_sptlrpc);
+               if (cld->cld_params)
+                       config_log_put(cld->cld_params);
+               if (cld->cld_nodemap)
+                       config_log_put(cld->cld_nodemap);
+               if (cld_is_sptlrpc(cld))
+                       sptlrpc_conf_log_stop(cld->cld_logname);
+
+               class_export_put(cld->cld_mgcexp);
+               OBD_FREE(cld, sizeof(*cld) + strlen(cld->cld_logname) + 1);
+       }
 
-        EXIT;
+       EXIT;
 }
 
 /* Find a config log by name */
@@ -173,80 +180,84 @@ struct config_llog_data *config_log_find(char *logname,
         LASSERT(logname != NULL);
 
         instance = cfg ? cfg->cfg_instance : NULL;
-        cfs_spin_lock(&config_list_lock);
-        cfs_list_for_each_entry(cld, &config_llog_list, cld_list_chain) {
+       spin_lock(&config_list_lock);
+       list_for_each_entry(cld, &config_llog_list, cld_list_chain) {
                 /* check if instance equals */
                 if (instance != cld->cld_cfg.cfg_instance)
                         continue;
 
-                /* instance may be NULL, should check name */
-                if (strcmp(logname, cld->cld_logname) == 0) {
-                        found = cld;
-                        break;
-                }
-        }
-        if (found) {
-                cfs_atomic_inc(&found->cld_refcount);
-                LASSERT(found->cld_stopping == 0 || cld_is_sptlrpc(found) == 0);
-        }
-        cfs_spin_unlock(&config_list_lock);
-        RETURN(found);
+               /* instance may be NULL, should check name */
+               if (strcmp(logname, cld->cld_logname) == 0) {
+                       found = cld;
+                       break;
+               }
+       }
+       if (found) {
+               atomic_inc(&found->cld_refcount);
+               LASSERT(found->cld_stopping == 0 || cld_is_sptlrpc(found) == 0);
+       }
+       spin_unlock(&config_list_lock);
+       RETURN(found);
 }
 
 static
 struct config_llog_data *do_config_log_add(struct obd_device *obd,
-                                           char *logname,
-                                           int type,
-                                           struct config_llog_instance *cfg,
-                                           struct super_block *sb)
+                                          char *logname,
+                                          int type,
+                                          struct config_llog_instance *cfg,
+                                          struct super_block *sb)
 {
-        struct config_llog_data *cld;
-        int                      rc;
-        ENTRY;
-
-        CDEBUG(D_MGC, "do adding config log %s:%p\n", logname,
-               cfg ? cfg->cfg_instance : 0);
-
-        OBD_ALLOC(cld, sizeof(*cld) + strlen(logname) + 1);
-        if (!cld)
-                RETURN(ERR_PTR(-ENOMEM));
-
-        strcpy(cld->cld_logname, logname);
-        if (cfg)
-                cld->cld_cfg = *cfg;
-        cfs_mutex_init(&cld->cld_lock);
-        cld->cld_cfg.cfg_last_idx = 0;
-        cld->cld_cfg.cfg_flags = 0;
-        cld->cld_cfg.cfg_sb = sb;
-        cld->cld_type = type;
-        cfs_atomic_set(&cld->cld_refcount, 1);
-
-        /* Keep the mgc around until we are done */
-        cld->cld_mgcexp = class_export_get(obd->obd_self_export);
-
-        if (cld_is_sptlrpc(cld)) {
-                sptlrpc_conf_log_start(logname);
-                cld->cld_cfg.cfg_obdname = obd->obd_name;
-        }
+       struct config_llog_data *cld;
+       int rc;
+
+       ENTRY;
+
+       CDEBUG(D_MGC, "do adding config log %s:%p\n", logname,
+              cfg ? cfg->cfg_instance : NULL);
+
+       OBD_ALLOC(cld, sizeof(*cld) + strlen(logname) + 1);
+       if (!cld)
+               RETURN(ERR_PTR(-ENOMEM));
+
+       strcpy(cld->cld_logname, logname);
+       if (cfg)
+               cld->cld_cfg = *cfg;
+       else
+               cld->cld_cfg.cfg_callback = class_config_llog_handler;
+       mutex_init(&cld->cld_lock);
+       cld->cld_cfg.cfg_last_idx = 0;
+       cld->cld_cfg.cfg_flags = 0;
+       cld->cld_cfg.cfg_sb = sb;
+       cld->cld_type = type;
+       atomic_set(&cld->cld_refcount, 1);
+
+       /* Keep the mgc around until we are done */
+       cld->cld_mgcexp = class_export_get(obd->obd_self_export);
+
+       if (cld_is_sptlrpc(cld)) {
+               sptlrpc_conf_log_start(logname);
+               cld->cld_cfg.cfg_obdname = obd->obd_name;
+       }
 
-        rc = mgc_logname2resid(logname, &cld->cld_resid, type);
+       rc = mgc_logname2resid(logname, &cld->cld_resid, type);
 
-        cfs_spin_lock(&config_list_lock);
-        cfs_list_add(&cld->cld_list_chain, &config_llog_list);
-        cfs_spin_unlock(&config_list_lock);
+       spin_lock(&config_list_lock);
+       list_add(&cld->cld_list_chain, &config_llog_list);
+       spin_unlock(&config_list_lock);
 
-        if (rc) {
-                config_log_put(cld);
-                RETURN(ERR_PTR(rc));
-        }
+       if (rc) {
+               config_log_put(cld);
+               RETURN(ERR_PTR(rc));
+       }
 
-        if (cld_is_sptlrpc(cld)) {
-                rc = mgc_process_log(obd, cld);
-                if (rc)
-                        CERROR("failed processing sptlrpc log: %d\n", rc);
-        }
+       if (cld_is_sptlrpc(cld) || cld_is_nodemap(cld)) {
+               rc = mgc_process_log(obd, cld);
+               if (rc && rc != -ENOENT)
+                       CERROR("%s: failed processing log, type %d: rc = %d\n",
+                              obd->obd_name, type, rc);
+       }
 
-        RETURN(cld);
+       RETURN(cld);
 }
 
 static struct config_llog_data *config_recover_log_add(struct obd_device *obd,
@@ -262,6 +273,10 @@ static struct config_llog_data *config_recover_log_add(struct obd_device *obd,
        if (IS_OST(lsi))
                 return NULL;
 
+       /* for osp-on-ost, see lustre_start_osp() */
+       if (IS_MDT(lsi) && lcfg.cfg_instance)
+               return NULL;
+
         /* we have to use different llog for clients and mdts for cmd
          * where only clients are notified if one of cmd server restarts */
         LASSERT(strlen(fsname) < sizeof(logname) / 2);
@@ -279,6 +294,19 @@ static struct config_llog_data *config_recover_log_add(struct obd_device *obd,
         return cld;
 }
 
+static struct config_llog_data *config_params_log_add(struct obd_device *obd,
+       struct config_llog_instance *cfg, struct super_block *sb)
+{
+       struct config_llog_instance     lcfg = *cfg;
+       struct config_llog_data         *cld;
+
+       lcfg.cfg_instance = sb;
+
+       cld = do_config_log_add(obd, PARAMS_FILENAME, CONFIG_T_PARAMS,
+                               &lcfg, sb);
+
+       return cld;
+}
 
 /** Add this log to the list of active logs watched by an MGC.
  * Active means we're watching for updates.
@@ -286,181 +314,259 @@ static struct config_llog_data *config_recover_log_add(struct obd_device *obd,
  * Each instance may be at a different point in the log.
  */
 static int config_log_add(struct obd_device *obd, char *logname,
-                          struct config_llog_instance *cfg,
-                          struct super_block *sb)
+                         struct config_llog_instance *cfg,
+                         struct super_block *sb)
 {
-        struct lustre_sb_info *lsi = s2lsi(sb);
-        struct config_llog_data *cld;
-        struct config_llog_data *sptlrpc_cld;
-        char                     seclogname[32];
-        char                    *ptr;
-        ENTRY;
+       struct lustre_sb_info   *lsi = s2lsi(sb);
+       struct config_llog_data *cld;
+       struct config_llog_data *sptlrpc_cld;
+       struct config_llog_data *params_cld;
+       struct config_llog_data *nodemap_cld;
+       char                    seclogname[32];
+       char                    *ptr;
+       int                     rc;
+       ENTRY;
+
+       CDEBUG(D_MGC, "adding config log %s:%p\n", logname, cfg->cfg_instance);
+
+       /*
+        * for each regular log, the depended sptlrpc log name is
+        * <fsname>-sptlrpc. multiple regular logs may share one sptlrpc log.
+        */
+       ptr = strrchr(logname, '-');
+       if (ptr == NULL || ptr - logname > 8) {
+               CERROR("logname %s is too long\n", logname);
+               RETURN(-EINVAL);
+       }
 
-        CDEBUG(D_MGC, "adding config log %s:%p\n", logname, cfg->cfg_instance);
+       memcpy(seclogname, logname, ptr - logname);
+       strcpy(seclogname + (ptr - logname), "-sptlrpc");
 
-        /*
-         * for each regular log, the depended sptlrpc log name is
-         * <fsname>-sptlrpc. multiple regular logs may share one sptlrpc log.
-         */
-        ptr = strrchr(logname, '-');
-        if (ptr == NULL || ptr - logname > 8) {
-                CERROR("logname %s is too long\n", logname);
-                RETURN(-EINVAL);
-        }
+       sptlrpc_cld = config_log_find(seclogname, NULL);
+       if (sptlrpc_cld == NULL) {
+               sptlrpc_cld = do_config_log_add(obd, seclogname,
+                                               CONFIG_T_SPTLRPC, NULL, NULL);
+               if (IS_ERR(sptlrpc_cld)) {
+                       CERROR("can't create sptlrpc log: %s\n", seclogname);
+                       GOTO(out, rc = PTR_ERR(sptlrpc_cld));
+               }
+       }
 
-        memcpy(seclogname, logname, ptr - logname);
-        strcpy(seclogname + (ptr - logname), "-sptlrpc");
+       nodemap_cld = config_log_find(LUSTRE_NODEMAP_NAME, NULL);
+       if (!nodemap_cld && IS_SERVER(lsi) && !IS_MGS(lsi)) {
+               nodemap_cld = do_config_log_add(obd, LUSTRE_NODEMAP_NAME,
+                                               CONFIG_T_NODEMAP, NULL, NULL);
+               if (IS_ERR(nodemap_cld)) {
+                       rc = PTR_ERR(nodemap_cld);
+                       CERROR("%s: cannot create nodemap log: rc = %d\n",
+                              obd->obd_name, rc);
+                       GOTO(out_sptlrpc, rc);
+               }
+       }
 
-        sptlrpc_cld = config_log_find(seclogname, NULL);
-        if (sptlrpc_cld == NULL) {
-                sptlrpc_cld = do_config_log_add(obd, seclogname,
-                                                CONFIG_T_SPTLRPC, NULL, NULL);
-                if (IS_ERR(sptlrpc_cld)) {
-                        CERROR("can't create sptlrpc log: %s\n", seclogname);
-                        RETURN(PTR_ERR(sptlrpc_cld));
-                }
-        }
+       params_cld = config_params_log_add(obd, cfg, sb);
+       if (IS_ERR(params_cld)) {
+               rc = PTR_ERR(params_cld);
+               CERROR("%s: can't create params log: rc = %d\n",
+                      obd->obd_name, rc);
+               GOTO(out_nodemap, rc);
+       }
 
-        cld = do_config_log_add(obd, logname, CONFIG_T_CONFIG, cfg, sb);
-        if (IS_ERR(cld)) {
-                CERROR("can't create log: %s\n", logname);
-                config_log_put(sptlrpc_cld);
-                RETURN(PTR_ERR(cld));
-        }
+       cld = do_config_log_add(obd, logname, CONFIG_T_CONFIG, cfg, sb);
+       if (IS_ERR(cld)) {
+               CERROR("can't create log: %s\n", logname);
+               GOTO(out_params, rc = PTR_ERR(cld));
+       }
 
-        cld->cld_sptlrpc = sptlrpc_cld;
+       LASSERT(lsi->lsi_lmd);
+       if (!(lsi->lsi_lmd->lmd_flags & LMD_FLG_NOIR)) {
+               struct config_llog_data *recover_cld;
+               ptr = strrchr(seclogname, '-');
+               if (ptr != NULL) {
+                       *ptr = 0;
+               }
+               else {
+                       CERROR("%s: sptlrpc log name not correct, %s: "
+                              "rc = %d\n", obd->obd_name, seclogname, -EINVAL);
+                       config_log_put(cld);
+                       RETURN(-EINVAL);
+               }
+               recover_cld = config_recover_log_add(obd, seclogname, cfg, sb);
+               if (IS_ERR(recover_cld))
+                       GOTO(out_cld, rc = PTR_ERR(recover_cld));
+               cld->cld_recover = recover_cld;
+       }
 
-        LASSERT(lsi->lsi_lmd);
-        if (!(lsi->lsi_lmd->lmd_flags & LMD_FLG_NOIR)) {
-                struct config_llog_data *recover_cld;
-                *strrchr(seclogname, '-') = 0;
-                recover_cld = config_recover_log_add(obd, seclogname, cfg, sb);
-                if (IS_ERR(recover_cld)) {
-                        config_log_put(cld);
-                        RETURN(PTR_ERR(recover_cld));
-                }
-                cld->cld_recover = recover_cld;
-        }
+       cld->cld_sptlrpc = sptlrpc_cld;
+       cld->cld_params = params_cld;
+       cld->cld_nodemap = nodemap_cld;
 
-        RETURN(0);
+       RETURN(0);
+
+out_cld:
+       config_log_put(cld);
+
+out_params:
+       config_log_put(params_cld);
+
+out_nodemap:
+       config_log_put(nodemap_cld);
+
+out_sptlrpc:
+       config_log_put(sptlrpc_cld);
+
+out:
+       return rc;
 }
 
-CFS_DEFINE_MUTEX(llog_process_lock);
+DEFINE_MUTEX(llog_process_lock);
 
 /** Stop watching for updates on this log.
  */
 static int config_log_end(char *logname, struct config_llog_instance *cfg)
 {
-        struct config_llog_data *cld;
-        struct config_llog_data *cld_sptlrpc = NULL;
-        struct config_llog_data *cld_recover = NULL;
-        int rc = 0;
-        ENTRY;
-
-        cld = config_log_find(logname, cfg);
-        if (cld == NULL)
-                RETURN(-ENOENT);
-
-        cfs_mutex_lock(&cld->cld_lock);
-        /*
-         * if cld_stopping is set, it means we didn't start the log thus
-         * not owning the start ref. this can happen after previous umount:
-         * the cld still hanging there waiting for lock cancel, and we
-         * remount again but failed in the middle and call log_end without
-         * calling start_log.
-         */
-        if (unlikely(cld->cld_stopping)) {
-                cfs_mutex_unlock(&cld->cld_lock);
-                /* drop the ref from the find */
-                config_log_put(cld);
-                RETURN(rc);
-        }
+       struct config_llog_data *cld;
+       struct config_llog_data *cld_sptlrpc = NULL;
+       struct config_llog_data *cld_params = NULL;
+       struct config_llog_data *cld_recover = NULL;
+       struct config_llog_data *cld_nodemap = NULL;
+       int rc = 0;
+
+       ENTRY;
+
+       cld = config_log_find(logname, cfg);
+       if (cld == NULL)
+               RETURN(-ENOENT);
+
+       mutex_lock(&cld->cld_lock);
+       /*
+        * if cld_stopping is set, it means we didn't start the log thus
+        * not owning the start ref. this can happen after previous umount:
+        * the cld still hanging there waiting for lock cancel, and we
+        * remount again but failed in the middle and call log_end without
+        * calling start_log.
+        */
+       if (unlikely(cld->cld_stopping)) {
+               mutex_unlock(&cld->cld_lock);
+               /* drop the ref from the find */
+               config_log_put(cld);
+               RETURN(rc);
+       }
 
-        cld->cld_stopping = 1;
+       cld->cld_stopping = 1;
 
-        cld_recover = cld->cld_recover;
-        cld->cld_recover = NULL;
-        cfs_mutex_unlock(&cld->cld_lock);
+       cld_recover = cld->cld_recover;
+       cld->cld_recover = NULL;
+       mutex_unlock(&cld->cld_lock);
 
-        if (cld_recover) {
-                cfs_mutex_lock(&cld_recover->cld_lock);
-                cld_recover->cld_stopping = 1;
-                cfs_mutex_unlock(&cld_recover->cld_lock);
-                config_log_put(cld_recover);
-        }
+       if (cld_recover) {
+               mutex_lock(&cld_recover->cld_lock);
+               cld_recover->cld_stopping = 1;
+               mutex_unlock(&cld_recover->cld_lock);
+               config_log_put(cld_recover);
+       }
 
-        cfs_spin_lock(&config_list_lock);
-        cld_sptlrpc = cld->cld_sptlrpc;
-        cld->cld_sptlrpc = NULL;
-        cfs_spin_unlock(&config_list_lock);
+       spin_lock(&config_list_lock);
+       cld_sptlrpc = cld->cld_sptlrpc;
+       cld->cld_sptlrpc = NULL;
+       cld_params = cld->cld_params;
+       cld->cld_params = NULL;
+       cld_nodemap = cld->cld_nodemap;
+       cld->cld_nodemap = NULL;
+       spin_unlock(&config_list_lock);
+
+       if (cld_sptlrpc)
+               config_log_put(cld_sptlrpc);
+
+       if (cld_params) {
+               mutex_lock(&cld_params->cld_lock);
+               cld_params->cld_stopping = 1;
+               mutex_unlock(&cld_params->cld_lock);
+               config_log_put(cld_params);
+       }
 
-        if (cld_sptlrpc)
-                config_log_put(cld_sptlrpc);
+       /* don't set cld_stopping on nm lock as other targets may be active */
+       if (cld_nodemap)
+               config_log_put(cld_nodemap);
 
-        /* drop the ref from the find */
-        config_log_put(cld);
-        /* drop the start ref */
-        config_log_put(cld);
+       /* drop the ref from the find */
+       config_log_put(cld);
+       /* drop the start ref */
+       config_log_put(cld);
 
-        CDEBUG(D_MGC, "end config log %s (%d)\n", logname ? logname : "client",
-               rc);
-        RETURN(rc);
+       CDEBUG(D_MGC, "end config log %s (%d)\n", logname ? logname : "client",
+              rc);
+       RETURN(rc);
 }
 
-int lprocfs_mgc_rd_ir_state(char *page, char **start, off_t off,
-                            int count, int *eof, void *data)
+#ifdef CONFIG_PROC_FS
+int lprocfs_mgc_rd_ir_state(struct seq_file *m, void *data)
 {
-        struct obd_device       *obd = data;
-        struct obd_import       *imp = obd->u.cli.cl_import;
-        struct obd_connect_data *ocd = &imp->imp_connect_data;
-        struct config_llog_data *cld;
-        int rc = 0;
-        ENTRY;
-
-        rc = snprintf(page, count, "imperative_recovery: %s\n",
-                     OCD_HAS_FLAG(ocd, IMP_RECOV) ? "ENABLED" : "DISABLED");
-        rc += snprintf(page + rc, count - rc, "client_state:\n");
-
-        cfs_spin_lock(&config_list_lock);
-        cfs_list_for_each_entry(cld, &config_llog_list, cld_list_chain) {
-                if (cld->cld_recover == NULL)
-                        continue;
-                rc += snprintf(page + rc, count - rc,
-                               "    - { client: %s, nidtbl_version: %u }\n",
-                               cld->cld_logname,
-                               cld->cld_recover->cld_cfg.cfg_last_idx);
-        }
-        cfs_spin_unlock(&config_list_lock);
+       struct obd_device       *obd = data;
+       struct obd_import       *imp;
+       struct obd_connect_data *ocd;
+       struct config_llog_data *cld;
+       ENTRY;
+
+       LASSERT(obd != NULL);
+       LPROCFS_CLIMP_CHECK(obd);
+       imp = obd->u.cli.cl_import;
+       ocd = &imp->imp_connect_data;
+
+       seq_printf(m, "imperative_recovery: %s\n",
+                  OCD_HAS_FLAG(ocd, IMP_RECOV) ? "ENABLED" : "DISABLED");
+       seq_printf(m, "client_state:\n");
+
+       spin_lock(&config_list_lock);
+       list_for_each_entry(cld, &config_llog_list, cld_list_chain) {
+               if (cld->cld_recover == NULL)
+                       continue;
+               seq_printf(m,  "    - { client: %s, nidtbl_version: %u }\n",
+                          cld->cld_logname,
+                          cld->cld_recover->cld_cfg.cfg_last_idx);
+       }
+       spin_unlock(&config_list_lock);
 
-        RETURN(rc);
+       LPROCFS_CLIMP_EXIT(obd);
+       RETURN(0);
 }
+#endif
 
 /* reenqueue any lost locks */
-#define RQ_RUNNING 0x1
-#define RQ_NOW     0x2
-#define RQ_LATER   0x4
-#define RQ_STOP    0x8
+#define RQ_RUNNING     0x1
+#define RQ_NOW         0x2
+#define RQ_LATER       0x4
+#define RQ_STOP                0x8
+#define RQ_PRECLEANUP  0x10
 static int                    rq_state = 0;
-static cfs_waitq_t            rq_waitq;
-static CFS_DECLARE_COMPLETION(rq_exit);
+static wait_queue_head_t      rq_waitq;
+static DECLARE_COMPLETION(rq_exit);
+static DECLARE_COMPLETION(rq_start);
 
 static void do_requeue(struct config_llog_data *cld)
 {
-        ENTRY;
-        LASSERT(cfs_atomic_read(&cld->cld_refcount) > 0);
-
-        /* Do not run mgc_process_log on a disconnected export or an
-           export which is being disconnected. Take the client
-           semaphore to make the check non-racy. */
-        cfs_down_read(&cld->cld_mgcexp->exp_obd->u.cli.cl_sem);
-        if (cld->cld_mgcexp->exp_obd->u.cli.cl_conn_count != 0) {
-                CDEBUG(D_MGC, "updating log %s\n", cld->cld_logname);
-                mgc_process_log(cld->cld_mgcexp->exp_obd, cld);
-        } else {
-                CDEBUG(D_MGC, "disconnecting, won't update log %s\n",
-                       cld->cld_logname);
-        }
-        cfs_up_read(&cld->cld_mgcexp->exp_obd->u.cli.cl_sem);
+       int rc = 0;
+       ENTRY;
+
+       LASSERT(atomic_read(&cld->cld_refcount) > 0);
+
+       /*
+        * Do not run mgc_process_log on a disconnected export or an
+        * export which is being disconnected. Take the client
+        * semaphore to make the check non-racy.
+        */
+       down_read_nested(&cld->cld_mgcexp->exp_obd->u.cli.cl_sem,
+                        OBD_CLI_SEM_MGC);
+       if (cld->cld_mgcexp->exp_obd->u.cli.cl_conn_count != 0) {
+               CDEBUG(D_MGC, "updating log %s\n", cld->cld_logname);
+               rc = mgc_process_log(cld->cld_mgcexp->exp_obd, cld);
+               if (rc && rc != -ENOENT)
+                       CERROR("failed processing log: %d\n", rc);
+       } else {
+               CDEBUG(D_MGC, "disconnecting, won't update log %s\n",
+                      cld->cld_logname);
+       }
+       up_read(&cld->cld_mgcexp->exp_obd->u.cli.cl_sem);
 
         EXIT;
 }
@@ -474,35 +580,40 @@ static void do_requeue(struct config_llog_data *cld)
 
 static int mgc_requeue_thread(void *data)
 {
-        char name[] = "ll_cfg_requeue";
-        int rc = 0;
-        ENTRY;
-
-        cfs_daemonize(name);
-
-        CDEBUG(D_MGC, "Starting requeue thread\n");
-
-        /* Keep trying failed locks periodically */
-        cfs_spin_lock(&config_list_lock);
-        rq_state |= RQ_RUNNING;
-        while (1) {
-                struct l_wait_info lwi;
-                struct config_llog_data *cld, *cld_prev;
-                int rand = cfs_rand() & MGC_TIMEOUT_RAND_CENTISEC;
-                int stopped = !!(rq_state & RQ_STOP);
-                int to;
-
-                /* Any new or requeued lostlocks will change the state */
-                rq_state &= ~(RQ_NOW | RQ_LATER);
-                cfs_spin_unlock(&config_list_lock);
+       int rc = 0;
+       bool first = true;
+       ENTRY;
+
+       CDEBUG(D_MGC, "Starting requeue thread\n");
+
+       /* Keep trying failed locks periodically */
+       spin_lock(&config_list_lock);
+       rq_state |= RQ_RUNNING;
+       while (1) {
+               struct l_wait_info lwi;
+               struct config_llog_data *cld, *cld_prev;
+               int rand = cfs_rand() & MGC_TIMEOUT_RAND_CENTISEC;
+               int stopped = !!(rq_state & RQ_STOP);
+               int to;
+
+               /* Any new or requeued lostlocks will change the state */
+               rq_state &= ~(RQ_NOW | RQ_LATER);
+               spin_unlock(&config_list_lock);
+
+               if (first) {
+                       first = false;
+                       complete(&rq_start);
+               }
 
-                /* Always wait a few seconds to allow the server who
-                   caused the lock revocation to finish its setup, plus some
-                   random so everyone doesn't try to reconnect at once. */
-                to = MGC_TIMEOUT_MIN_SECONDS * CFS_HZ;
-                to += rand * CFS_HZ / 100; /* rand is centi-seconds */
-                lwi = LWI_TIMEOUT(to, NULL, NULL);
-                l_wait_event(rq_waitq, rq_state & RQ_STOP, &lwi);
+               /* Always wait a few seconds to allow the server who
+                  caused the lock revocation to finish its setup, plus some
+                  random so everyone doesn't try to reconnect at once. */
+               to = msecs_to_jiffies(MGC_TIMEOUT_MIN_SECONDS * MSEC_PER_SEC);
+               /* rand is centi-seconds */
+               to += msecs_to_jiffies(rand * MSEC_PER_SEC / 100);
+               lwi = LWI_TIMEOUT(to, NULL, NULL);
+               l_wait_event(rq_waitq, rq_state & (RQ_STOP | RQ_PRECLEANUP),
+                            &lwi);
 
                 /*
                  * iterate & processing through the list. for each cld, process
@@ -514,226 +625,291 @@ static int mgc_requeue_thread(void *data)
                  */
                 cld_prev = NULL;
 
-                cfs_spin_lock(&config_list_lock);
-                cfs_list_for_each_entry(cld, &config_llog_list,
-                                        cld_list_chain) {
-                        if (!cld->cld_lostlock)
-                                continue;
+               spin_lock(&config_list_lock);
+               rq_state &= ~RQ_PRECLEANUP;
+               list_for_each_entry(cld, &config_llog_list,
+                                       cld_list_chain) {
+                       if (!cld->cld_lostlock)
+                               continue;
 
-                        cfs_spin_unlock(&config_list_lock);
+                       spin_unlock(&config_list_lock);
 
-                        LASSERT(cfs_atomic_read(&cld->cld_refcount) > 0);
+                       LASSERT(atomic_read(&cld->cld_refcount) > 0);
 
-                        /* Whether we enqueued again or not in mgc_process_log,
-                         * we're done with the ref from the old enqueue */
-                        if (cld_prev)
-                                config_log_put(cld_prev);
-                        cld_prev = cld;
+                       /* Whether we enqueued again or not in mgc_process_log,
+                        * we're done with the ref from the old enqueue */
+                       if (cld_prev)
+                               config_log_put(cld_prev);
+                       cld_prev = cld;
 
                         cld->cld_lostlock = 0;
-                        if (likely(!stopped))
-                                do_requeue(cld);
+                       if (likely(!stopped))
+                               do_requeue(cld);
 
-                        cfs_spin_lock(&config_list_lock);
-                }
-                cfs_spin_unlock(&config_list_lock);
-                if (cld_prev)
-                        config_log_put(cld_prev);
-
-                /* break after scanning the list so that we can drop
-                 * refcount to losing lock clds */
-                if (unlikely(stopped)) {
-                        cfs_spin_lock(&config_list_lock);
-                        break;
-                }
+                       spin_lock(&config_list_lock);
+               }
+               spin_unlock(&config_list_lock);
+               if (cld_prev)
+                       config_log_put(cld_prev);
+
+               /* break after scanning the list so that we can drop
+                * refcount to losing lock clds */
+               if (unlikely(stopped)) {
+                       spin_lock(&config_list_lock);
+                       break;
+               }
 
-                /* Wait a bit to see if anyone else needs a requeue */
-                lwi = (struct l_wait_info) { 0 };
-                l_wait_event(rq_waitq, rq_state & (RQ_NOW | RQ_STOP),
-                             &lwi);
-                cfs_spin_lock(&config_list_lock);
-        }
-        /* spinlock and while guarantee RQ_NOW and RQ_LATER are not set */
-        rq_state &= ~RQ_RUNNING;
-        cfs_spin_unlock(&config_list_lock);
+               /* Wait a bit to see if anyone else needs a requeue */
+               lwi = (struct l_wait_info) { 0 };
+               l_wait_event(rq_waitq, rq_state & (RQ_NOW | RQ_STOP),
+                            &lwi);
+               spin_lock(&config_list_lock);
+       }
+       /* spinlock and while guarantee RQ_NOW and RQ_LATER are not set */
+       rq_state &= ~RQ_RUNNING;
+       spin_unlock(&config_list_lock);
 
-        cfs_complete(&rq_exit);
+       complete(&rq_exit);
 
-        CDEBUG(D_MGC, "Ending requeue thread\n");
-        RETURN(rc);
+       CDEBUG(D_MGC, "Ending requeue thread\n");
+       RETURN(rc);
 }
 
 /* Add a cld to the list to requeue.  Start the requeue thread if needed.
    We are responsible for dropping the config log reference from here on out. */
 static void mgc_requeue_add(struct config_llog_data *cld)
 {
-        ENTRY;
+       ENTRY;
 
-        CDEBUG(D_INFO, "log %s: requeue (r=%d sp=%d st=%x)\n",
-               cld->cld_logname, cfs_atomic_read(&cld->cld_refcount),
-               cld->cld_stopping, rq_state);
-        LASSERT(cfs_atomic_read(&cld->cld_refcount) > 0);
+       CDEBUG(D_INFO, "log %s: requeue (r=%d sp=%d st=%x)\n",
+               cld->cld_logname, atomic_read(&cld->cld_refcount),
+               cld->cld_stopping, rq_state);
+       LASSERT(atomic_read(&cld->cld_refcount) > 0);
 
-        cfs_mutex_lock(&cld->cld_lock);
-        if (cld->cld_stopping || cld->cld_lostlock) {
-                cfs_mutex_unlock(&cld->cld_lock);
-                RETURN_EXIT;
-        }
-        /* this refcount will be released in mgc_requeue_thread. */
-        config_log_get(cld);
-        cld->cld_lostlock = 1;
-        cfs_mutex_unlock(&cld->cld_lock);
-
-        /* Hold lock for rq_state */
-        cfs_spin_lock(&config_list_lock);
-        if (rq_state & RQ_STOP) {
-                cfs_spin_unlock(&config_list_lock);
-                cld->cld_lostlock = 0;
-                config_log_put(cld);
-        } else {
-                rq_state |= RQ_NOW;
-                cfs_spin_unlock(&config_list_lock);
-                cfs_waitq_signal(&rq_waitq);
-        }
-        EXIT;
+       mutex_lock(&cld->cld_lock);
+       if (cld->cld_stopping || cld->cld_lostlock) {
+               mutex_unlock(&cld->cld_lock);
+               RETURN_EXIT;
+       }
+       /* this refcount will be released in mgc_requeue_thread. */
+       config_log_get(cld);
+       cld->cld_lostlock = 1;
+       mutex_unlock(&cld->cld_lock);
+
+       /* Hold lock for rq_state */
+       spin_lock(&config_list_lock);
+       if (rq_state & RQ_STOP) {
+               spin_unlock(&config_list_lock);
+               cld->cld_lostlock = 0;
+               config_log_put(cld);
+       } else {
+               rq_state |= RQ_NOW;
+               spin_unlock(&config_list_lock);
+               wake_up(&rq_waitq);
+       }
+       EXIT;
 }
 
 /********************** class fns **********************/
+static int mgc_local_llog_init(const struct lu_env *env,
+                              struct obd_device *obd,
+                              struct obd_device *disk)
+{
+       struct llog_ctxt        *ctxt;
+       int                      rc;
+
+       ENTRY;
 
-static int mgc_fs_setup(struct obd_device *obd, struct super_block *sb,
-                        struct vfsmount *mnt)
+       rc = llog_setup(env, obd, &obd->obd_olg, LLOG_CONFIG_ORIG_CTXT, disk,
+                       &llog_osd_ops);
+       if (rc)
+               RETURN(rc);
+
+       ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
+       LASSERT(ctxt);
+       ctxt->loc_dir = obd->u.cli.cl_mgc_configs_dir;
+       llog_ctxt_put(ctxt);
+
+       RETURN(0);
+}
+
+static int mgc_local_llog_fini(const struct lu_env *env,
+                              struct obd_device *obd)
 {
-        struct lvfs_run_ctxt saved;
-        struct lustre_sb_info *lsi = s2lsi(sb);
-        struct client_obd *cli = &obd->u.cli;
-        struct dentry *dentry;
-        char *label;
-        int err = 0;
-        ENTRY;
+       struct llog_ctxt *ctxt;
 
-        LASSERT(lsi);
-        LASSERT(lsi->lsi_srv_mnt == mnt);
+       ENTRY;
 
-        /* The mgc fs exclusion sem. Only one fs can be setup at a time. */
-        cfs_down(&cli->cl_mgc_sem);
+       ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
+       llog_cleanup(env, ctxt);
 
-        cfs_cleanup_group_info();
+       RETURN(0);
+}
 
-       obd->obd_fsops = fsfilt_get_ops(lsi->lsi_fstype);
-        if (IS_ERR(obd->obd_fsops)) {
-                cfs_up(&cli->cl_mgc_sem);
-               CERROR("No fstype %s rc=%ld\n", lsi->lsi_fstype,
-                       PTR_ERR(obd->obd_fsops));
-                RETURN(PTR_ERR(obd->obd_fsops));
-        }
+static int mgc_fs_setup(const struct lu_env *env, struct obd_device *obd,
+                       struct super_block *sb)
+{
+       struct lustre_sb_info   *lsi = s2lsi(sb);
+       struct client_obd       *cli = &obd->u.cli;
+       struct lu_fid            rfid, fid;
+       struct dt_object        *root, *dto;
+       int                      rc = 0;
 
-        cli->cl_mgc_vfsmnt = mnt;
-        err = fsfilt_setup(obd, mnt->mnt_sb);
-        if (err)
-                GOTO(err_ops, err);
-
-        OBD_SET_CTXT_MAGIC(&obd->obd_lvfs_ctxt);
-        obd->obd_lvfs_ctxt.pwdmnt = mnt;
-        obd->obd_lvfs_ctxt.pwd = mnt->mnt_root;
-        obd->obd_lvfs_ctxt.fs = get_ds();
-
-        push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
-        dentry = ll_lookup_one_len(MOUNT_CONFIGS_DIR, cfs_fs_pwd(current->fs),
-                                   strlen(MOUNT_CONFIGS_DIR));
-        pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
-        if (IS_ERR(dentry)) {
-                err = PTR_ERR(dentry);
-                CERROR("cannot lookup %s directory: rc = %d\n",
-                       MOUNT_CONFIGS_DIR, err);
-                GOTO(err_ops, err);
-        }
-        cli->cl_mgc_configs_dir = dentry;
+       ENTRY;
+
+       LASSERT(lsi);
+       LASSERT(lsi->lsi_dt_dev);
+
+       /* The mgc fs exclusion mutex. Only one fs can be setup at a time. */
+       mutex_lock(&cli->cl_mgc_mutex);
+
+       /* Setup the configs dir */
+       fid.f_seq = FID_SEQ_LOCAL_NAME;
+       fid.f_oid = 1;
+       fid.f_ver = 0;
+       rc = local_oid_storage_init(env, lsi->lsi_dt_dev, &fid,
+                                   &cli->cl_mgc_los);
+       if (rc)
+               RETURN(rc);
+
+       rc = dt_root_get(env, lsi->lsi_dt_dev, &rfid);
+       if (rc)
+               GOTO(out_los, rc);
 
-        /* We take an obd ref to insure that we can't get to mgc_cleanup
-           without calling mgc_fs_cleanup first. */
-        class_incref(obd, "mgc_fs", obd);
+       root = dt_locate_at(env, lsi->lsi_dt_dev, &rfid,
+                           &cli->cl_mgc_los->los_dev->dd_lu_dev, NULL);
+       if (unlikely(IS_ERR(root)))
+               GOTO(out_los, rc = PTR_ERR(root));
 
-        label = fsfilt_get_label(obd, mnt->mnt_sb);
-        if (label)
-                CDEBUG(D_MGC, "MGC using disk labelled=%s\n", label);
+       dto = local_file_find_or_create(env, cli->cl_mgc_los, root,
+                                       MOUNT_CONFIGS_DIR,
+                                       S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
+       lu_object_put_nocache(env, &root->do_lu);
+       if (IS_ERR(dto))
+               GOTO(out_los, rc = PTR_ERR(dto));
 
-        /* We keep the cl_mgc_sem until mgc_fs_cleanup */
-        RETURN(0);
+       cli->cl_mgc_configs_dir = dto;
 
-err_ops:
-        fsfilt_put_ops(obd->obd_fsops);
-        obd->obd_fsops = NULL;
-        cli->cl_mgc_vfsmnt = NULL;
-        cfs_up(&cli->cl_mgc_sem);
-        RETURN(err);
+       LASSERT(lsi->lsi_osd_exp->exp_obd->obd_lvfs_ctxt.dt);
+       rc = mgc_local_llog_init(env, obd, lsi->lsi_osd_exp->exp_obd);
+       if (rc)
+               GOTO(out_llog, rc);
+
+       /* We take an obd ref to insure that we can't get to mgc_cleanup
+        * without calling mgc_fs_cleanup first. */
+       class_incref(obd, "mgc_fs", obd);
+
+       /* We keep the cl_mgc_sem until mgc_fs_cleanup */
+       EXIT;
+out_llog:
+       if (rc) {
+               lu_object_put(env, &cli->cl_mgc_configs_dir->do_lu);
+               cli->cl_mgc_configs_dir = NULL;
+       }
+out_los:
+       if (rc < 0) {
+               local_oid_storage_fini(env, cli->cl_mgc_los);
+               cli->cl_mgc_los = NULL;
+               mutex_unlock(&cli->cl_mgc_mutex);
+       }
+       return rc;
 }
 
-static int mgc_fs_cleanup(struct obd_device *obd)
+static int mgc_fs_cleanup(const struct lu_env *env, struct obd_device *obd)
 {
-        struct client_obd *cli = &obd->u.cli;
-        int rc = 0;
-        ENTRY;
+       struct client_obd       *cli = &obd->u.cli;
+       ENTRY;
 
-        LASSERT(cli->cl_mgc_vfsmnt != NULL);
+       LASSERT(cli->cl_mgc_los != NULL);
 
-        if (cli->cl_mgc_configs_dir != NULL) {
-                struct lvfs_run_ctxt saved;
-                push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
-                l_dput(cli->cl_mgc_configs_dir);
-                cli->cl_mgc_configs_dir = NULL;
-                pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
-                class_decref(obd, "mgc_fs", obd);
-        }
+       mgc_local_llog_fini(env, obd);
 
-        cli->cl_mgc_vfsmnt = NULL;
-        if (obd->obd_fsops)
-                fsfilt_put_ops(obd->obd_fsops);
+       lu_object_put_nocache(env, &cli->cl_mgc_configs_dir->do_lu);
+       cli->cl_mgc_configs_dir = NULL;
 
-        cfs_up(&cli->cl_mgc_sem);
+       local_oid_storage_fini(env, cli->cl_mgc_los);
+       cli->cl_mgc_los = NULL;
 
-        RETURN(rc);
+       class_decref(obd, "mgc_fs", obd);
+       mutex_unlock(&cli->cl_mgc_mutex);
+
+       RETURN(0);
 }
 
-static cfs_atomic_t mgc_count = CFS_ATOMIC_INIT(0);
-static int mgc_precleanup(struct obd_device *obd, enum obd_cleanup_stage stage)
+static int mgc_llog_init(const struct lu_env *env, struct obd_device *obd)
 {
-        int rc = 0;
-        ENTRY;
+       struct llog_ctxt        *ctxt;
+       int                      rc;
 
-        switch (stage) {
-        case OBD_CLEANUP_EARLY:
-                break;
-        case OBD_CLEANUP_EXPORTS:
-                if (cfs_atomic_dec_and_test(&mgc_count)) {
-                        int running;
-                        /* stop requeue thread */
-                        cfs_spin_lock(&config_list_lock);
-                        running = rq_state & RQ_RUNNING;
-                        if (running)
-                                rq_state |= RQ_STOP;
-                        cfs_spin_unlock(&config_list_lock);
-                        if (running) {
-                                cfs_waitq_signal(&rq_waitq);
-                                cfs_wait_for_completion(&rq_exit);
-                        }
-                }
-                obd_cleanup_client_import(obd);
-                rc = obd_llog_finish(obd, 0);
-                if (rc != 0)
-                        CERROR("failed to cleanup llogging subsystems\n");
-                break;
-        }
-        RETURN(rc);
+       ENTRY;
+
+       /* setup only remote ctxt, the local disk context is switched per each
+        * filesystem during mgc_fs_setup() */
+       rc = llog_setup(env, obd, &obd->obd_olg, LLOG_CONFIG_REPL_CTXT, obd,
+                       &llog_client_ops);
+       if (rc)
+               RETURN(rc);
+
+       ctxt = llog_get_context(obd, LLOG_CONFIG_REPL_CTXT);
+       LASSERT(ctxt);
+
+       llog_initiator_connect(ctxt);
+       llog_ctxt_put(ctxt);
+
+       RETURN(0);
+}
+
+static int mgc_llog_fini(const struct lu_env *env, struct obd_device *obd)
+{
+       struct llog_ctxt *ctxt;
+
+       ENTRY;
+
+       ctxt = llog_get_context(obd, LLOG_CONFIG_REPL_CTXT);
+       if (ctxt)
+               llog_cleanup(env, ctxt);
+
+       RETURN(0);
+}
+
+
+static atomic_t mgc_count = ATOMIC_INIT(0);
+static int mgc_precleanup(struct obd_device *obd)
+{
+       int     rc = 0;
+       int     temp;
+       ENTRY;
+
+       if (atomic_dec_and_test(&mgc_count)) {
+               LASSERT(rq_state & RQ_RUNNING);
+               /* stop requeue thread */
+               temp = RQ_STOP;
+       } else {
+               /* wakeup requeue thread to clean our cld */
+               temp = RQ_NOW | RQ_PRECLEANUP;
+       }
+
+       spin_lock(&config_list_lock);
+       rq_state |= temp;
+       spin_unlock(&config_list_lock);
+       wake_up(&rq_waitq);
+
+       if (temp & RQ_STOP)
+               wait_for_completion(&rq_exit);
+       obd_cleanup_client_import(obd);
+
+       rc = mgc_llog_fini(NULL, obd);
+       if (rc != 0)
+               CERROR("failed to cleanup llogging subsystems\n");
+
+       RETURN(rc);
 }
 
 static int mgc_cleanup(struct obd_device *obd)
 {
-        struct client_obd *cli = &obd->u.cli;
         int rc;
         ENTRY;
 
-        LASSERT(cli->cl_mgc_vfsmnt == NULL);
-
         /* COMPAT_146 - old config logs may have added profiles we don't
            know about */
         if (obd->obd_type->typ_refcnt <= 1)
@@ -749,50 +925,55 @@ static int mgc_cleanup(struct obd_device *obd)
 
 static int mgc_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 {
-        struct lprocfs_static_vars lvars;
-        int rc;
-        ENTRY;
+       struct task_struct      *task;
+       int                      rc;
+       ENTRY;
 
-        ptlrpcd_addref();
-
-        rc = client_obd_setup(obd, lcfg);
-        if (rc)
-                GOTO(err_decref, rc);
-
-        rc = obd_llog_init(obd, &obd->obd_olg, obd, NULL);
-        if (rc) {
-                CERROR("failed to setup llogging subsystems\n");
-                GOTO(err_cleanup, rc);
-        }
+       rc = ptlrpcd_addref();
+       if (rc < 0)
+               RETURN(rc);
 
-        lprocfs_mgc_init_vars(&lvars);
-        lprocfs_obd_setup(obd, lvars.obd_vars);
-        sptlrpc_lprocfs_cliobd_attach(obd);
+       rc = client_obd_setup(obd, lcfg);
+       if (rc)
+               GOTO(err_decref, rc);
 
-        if (cfs_atomic_inc_return(&mgc_count) == 1) {
-                rq_state = 0;
-                cfs_waitq_init(&rq_waitq);
+       rc = mgc_llog_init(NULL, obd);
+       if (rc) {
+               CERROR("failed to setup llogging subsystems\n");
+               GOTO(err_cleanup, rc);
+       }
 
-                /* start requeue thread */
-                rc = cfs_create_thread(mgc_requeue_thread, NULL,
-                                       CFS_DAEMON_FLAGS);
-                if (rc < 0) {
-                        CERROR("%s: Cannot start requeue thread (%d),"
-                               "no more log updates!\n",
-                               obd->obd_name, rc);
-                        GOTO(err_cleanup, rc);
-                }
-                /* rc is the pid of mgc_requeue_thread. */
-                rc = 0;
-        }
+#ifdef CONFIG_PROC_FS
+       obd->obd_vars = lprocfs_mgc_obd_vars;
+       lprocfs_obd_setup(obd);
+#endif
+       sptlrpc_lprocfs_cliobd_attach(obd);
+
+       if (atomic_inc_return(&mgc_count) == 1) {
+               rq_state = 0;
+               init_waitqueue_head(&rq_waitq);
+
+               /* start requeue thread */
+               task = kthread_run(mgc_requeue_thread, NULL, "ll_cfg_requeue");
+               if (IS_ERR(task)) {
+                       rc = PTR_ERR(task);
+                       CERROR("%s: cannot start requeue thread: rc = %d; "
+                              "no more log updates\n",
+                              obd->obd_name, rc);
+                       GOTO(err_cleanup, rc);
+               }
+               /* rc is the task_struct pointer of mgc_requeue_thread. */
+               rc = 0;
+               wait_for_completion(&rq_start);
+       }
 
-        RETURN(rc);
+       RETURN(rc);
 
 err_cleanup:
-        client_obd_cleanup(obd);
+       client_obd_cleanup(obd);
 err_decref:
-        ptlrpcd_decref();
-        RETURN(rc);
+       ptlrpcd_decref();
+       RETURN(rc);
 }
 
 /* based on ll_mdc_blocking_ast */
@@ -809,39 +990,39 @@ static int mgc_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
                 /* mgs wants the lock, give it up... */
                 LDLM_DEBUG(lock, "MGC blocking CB");
                 ldlm_lock2handle(lock, &lockh);
-                rc = ldlm_cli_cancel(&lockh);
-                break;
-        case LDLM_CB_CANCELING:
-                /* We've given up the lock, prepare ourselves to update. */
-                LDLM_DEBUG(lock, "MGC cancel CB");
-
-                CDEBUG(D_MGC, "Lock res "LPX64" (%.8s)\n",
-                       lock->l_resource->lr_name.name[0],
-                       (char *)&lock->l_resource->lr_name.name[0]);
-
-                if (!cld) {
-                        CDEBUG(D_INFO, "missing data, won't requeue\n");
-                        break;
-                }
+               rc = ldlm_cli_cancel(&lockh, LCF_ASYNC);
+               break;
+       case LDLM_CB_CANCELING:
+               /* We've given up the lock, prepare ourselves to update. */
+               LDLM_DEBUG(lock, "MGC cancel CB");
+
+               CDEBUG(D_MGC, "Lock res "DLDLMRES" (%.8s)\n",
+                      PLDLMRES(lock->l_resource),
+                      (char *)&lock->l_resource->lr_name.name[0]);
+
+               if (!cld) {
+                       CDEBUG(D_INFO, "missing data, won't requeue\n");
+                       break;
+               }
 
-                /* held at mgc_process_log(). */
-                LASSERT(cfs_atomic_read(&cld->cld_refcount) > 0);
-                /* Are we done with this log? */
-                if (cld->cld_stopping) {
-                        CDEBUG(D_MGC, "log %s: stopping, won't requeue\n",
-                               cld->cld_logname);
-                        config_log_put(cld);
-                        break;
-                }
-                /* Make sure not to re-enqueue when the mgc is stopping
-                   (we get called from client_disconnect_export) */
-                if (!lock->l_conn_export ||
-                    !lock->l_conn_export->exp_obd->u.cli.cl_conn_count) {
-                        CDEBUG(D_MGC, "log %.8s: disconnecting, won't requeue\n",
-                               cld->cld_logname);
-                        config_log_put(cld);
-                        break;
-                }
+               /* held at mgc_process_log(). */
+               LASSERT(atomic_read(&cld->cld_refcount) > 0);
+               /* Are we done with this log? */
+               if (cld->cld_stopping) {
+                       CDEBUG(D_MGC, "log %s: stopping, won't requeue\n",
+                               cld->cld_logname);
+                       config_log_put(cld);
+                       break;
+               }
+               /* Make sure not to re-enqueue when the mgc is stopping
+                  (we get called from client_disconnect_export) */
+               if (lock->l_conn_export == NULL ||
+                   lock->l_conn_export->exp_obd->u.cli.cl_conn_count == 0) {
+                       CDEBUG(D_MGC, "log %.8s: disconnecting, won't requeue\n",
+                               cld->cld_logname);
+                       config_log_put(cld);
+                       break;
+               }
 
                 /* Re-enqueue now */
                 mgc_requeue_add(cld);
@@ -855,7 +1036,10 @@ static int mgc_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
 }
 
 /* Not sure where this should go... */
-#define  MGC_ENQUEUE_LIMIT 50
+/* This is the timeout value for MGS_CONNECT request plus a ping interval, such
+ * that we can have a chance to try the secondary MGS if any. */
+#define  MGC_ENQUEUE_LIMIT (INITIAL_CONNECT_TIMEOUT + (AT_OFF ? 0 : at_min) \
+                               + PING_INTERVAL)
 #define  MGC_TARGET_REG_LIMIT 10
 #define  MGC_SEND_PARAM_LIMIT 10
 
@@ -897,19 +1081,23 @@ static int mgc_set_mgs_param(struct obd_export *exp,
 }
 
 /* Take a config lock so we can get cancel notifications */
-static int mgc_enqueue(struct obd_export *exp, struct lov_stripe_md *lsm,
-                       __u32 type, ldlm_policy_data_t *policy, __u32 mode,
-                       int *flags, void *bl_cb, void *cp_cb, void *gl_cb,
-                       void *data, __u32 lvb_len, void *lvb_swabber,
-                       struct lustre_handle *lockh)
+static int mgc_enqueue(struct obd_export *exp, enum ldlm_type type,
+                      union ldlm_policy_data *policy, enum ldlm_mode mode,
+                      __u64 *flags, void *bl_cb, void *cp_cb, void *gl_cb,
+                      void *data, __u32 lvb_len, void *lvb_swabber,
+                      struct lustre_handle *lockh)
 {
-        struct config_llog_data *cld = (struct config_llog_data *)data;
-        struct ldlm_enqueue_info einfo = { type, mode, mgc_blocking_ast,
-                         ldlm_completion_ast, NULL, NULL, NULL };
-        struct ptlrpc_request *req;
-        int short_limit = cld_is_sptlrpc(cld);
-        int rc;
-        ENTRY;
+       struct config_llog_data *cld = (struct config_llog_data *)data;
+       struct ldlm_enqueue_info einfo = {
+               .ei_type        = type,
+               .ei_mode        = mode,
+               .ei_cb_bl       = mgc_blocking_ast,
+               .ei_cb_cp       = ldlm_completion_ast,
+       };
+       struct ptlrpc_request *req;
+       int short_limit = cld_is_sptlrpc(cld);
+       int rc;
+       ENTRY;
 
         CDEBUG(D_MGC, "Enqueue for %s (res "LPX64")\n", cld->cld_logname,
                cld->cld_resid.name[0]);
@@ -921,6 +1109,8 @@ static int mgc_enqueue(struct obd_export *exp, struct lov_stripe_md *lsm,
                                         LDLM_ENQUEUE);
         if (req == NULL)
                 RETURN(-ENOMEM);
+
+       req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER, 0);
         ptlrpc_request_set_replen(req);
 
         /* check if this is server or client */
@@ -932,32 +1122,32 @@ static int mgc_enqueue(struct obd_export *exp, struct lov_stripe_md *lsm,
         /* Limit how long we will wait for the enqueue to complete */
         req->rq_delay_limit = short_limit ? 5 : MGC_ENQUEUE_LIMIT;
         rc = ldlm_cli_enqueue(exp, &req, &einfo, &cld->cld_resid, NULL, flags,
-                              NULL, 0, lockh, 0);
+                             NULL, 0, LVB_T_NONE, lockh, 0);
         /* A failed enqueue should still call the mgc_blocking_ast,
            where it will be requeued if needed ("grant failed"). */
         ptlrpc_req_finished(req);
         RETURN(rc);
 }
 
-static int mgc_cancel(struct obd_export *exp, struct lov_stripe_md *md,
-                      __u32 mode, struct lustre_handle *lockh)
+static int mgc_cancel(struct obd_export *exp, enum ldlm_mode mode,
+                     struct lustre_handle *lockh)
 {
-        ENTRY;
+       ENTRY;
 
-        ldlm_lock_decref(lockh, mode);
+       ldlm_lock_decref(lockh, mode);
 
-        RETURN(0);
+       RETURN(0);
 }
 
 static void mgc_notify_active(struct obd_device *unused)
 {
-        /* wakeup mgc_requeue_thread to requeue mgc lock */
-        cfs_spin_lock(&config_list_lock);
-        rq_state |= RQ_NOW;
-        cfs_spin_unlock(&config_list_lock);
-        cfs_waitq_signal(&rq_waitq);
+       /* wakeup mgc_requeue_thread to requeue mgc lock */
+       spin_lock(&config_list_lock);
+       rq_state |= RQ_NOW;
+       spin_unlock(&config_list_lock);
+       wake_up(&rq_waitq);
 
-        /* TODO: Help the MGS rebuild nidtbl. -jay */
+       /* TODO: Help the MGS rebuild nidtbl. -jay */
 }
 
 /* Send target_reg message to MGS */
@@ -1000,9 +1190,10 @@ static int mgc_target_register(struct obd_export *exp,
         RETURN(rc);
 }
 
-int mgc_set_info_async(const struct lu_env *env, struct obd_export *exp,
-                       obd_count keylen, void *key, obd_count vallen,
-                       void *val, struct ptlrpc_request_set *set)
+static int mgc_set_info_async(const struct lu_env *env, struct obd_export *exp,
+                             u32 keylen, void *key,
+                             u32 vallen, void *val,
+                             struct ptlrpc_request_set *set)
 {
         int rc = -EINVAL;
         ENTRY;
@@ -1036,27 +1227,21 @@ int mgc_set_info_async(const struct lu_env *env, struct obd_export *exp,
                 rc =  mgc_target_register(exp, mti);
                 RETURN(rc);
         }
-        if (KEY_IS(KEY_SET_FS)) {
-                struct super_block *sb = (struct super_block *)val;
-                struct lustre_sb_info *lsi;
-                if (vallen != sizeof(struct super_block))
-                        RETURN(-EINVAL);
-                lsi = s2lsi(sb);
-                rc = mgc_fs_setup(exp->exp_obd, sb, lsi->lsi_srv_mnt);
-                if (rc) {
-                        CERROR("set_fs got %d\n", rc);
-                }
-                RETURN(rc);
-        }
-        if (KEY_IS(KEY_CLEAR_FS)) {
-                if (vallen != 0)
-                        RETURN(-EINVAL);
-                rc = mgc_fs_cleanup(exp->exp_obd);
-                if (rc) {
-                        CERROR("clear_fs got %d\n", rc);
-                }
-                RETURN(rc);
-        }
+       if (KEY_IS(KEY_SET_FS)) {
+               struct super_block *sb = (struct super_block *)val;
+
+               if (vallen != sizeof(struct super_block))
+                       RETURN(-EINVAL);
+
+               rc = mgc_fs_setup(env, exp->exp_obd, sb);
+               RETURN(rc);
+       }
+       if (KEY_IS(KEY_CLEAR_FS)) {
+               if (vallen != 0)
+                       RETURN(-EINVAL);
+               rc = mgc_fs_cleanup(env, exp->exp_obd);
+               RETURN(rc);
+       }
         if (KEY_IS(KEY_SET_INFO)) {
                 struct mgs_send_param *msp;
 
@@ -1112,8 +1297,7 @@ int mgc_set_info_async(const struct lu_env *env, struct obd_export *exp,
 }
 
 static int mgc_get_info(const struct lu_env *env, struct obd_export *exp,
-                        __u32 keylen, void *key, __u32 *vallen, void *val,
-                        struct lov_stripe_md *unused)
+                       __u32 keylen, void *key, __u32 *vallen, void *val)
 {
         int rc = -EINVAL;
 
@@ -1142,6 +1326,8 @@ static int mgc_import_event(struct obd_device *obd,
         switch (event) {
         case IMP_EVENT_DISCON:
                 /* MGC imports should not wait for recovery */
+               if (OCD_HAS_FLAG(&imp->imp_connect_data, IMP_RECOV))
+                       ptlrpc_pinger_ir_down();
                 break;
         case IMP_EVENT_INACTIVE:
                 break;
@@ -1150,12 +1336,14 @@ static int mgc_import_event(struct obd_device *obd,
                 ldlm_namespace_cleanup(ns, LDLM_FL_LOCAL_ONLY);
                 break;
         }
-        case IMP_EVENT_ACTIVE:
-                LCONSOLE_WARN("%s: Reactivating import\n", obd->obd_name);
-                /* Clearing obd_no_recov allows us to continue pinging */
-                obd->obd_no_recov = 0;
-                mgc_notify_active(obd);
-                break;
+       case IMP_EVENT_ACTIVE:
+               CDEBUG(D_INFO, "%s: Reactivating import\n", obd->obd_name);
+               /* Clearing obd_no_recov allows us to continue pinging */
+               obd->obd_no_recov = 0;
+               mgc_notify_active(obd);
+               if (OCD_HAS_FLAG(&imp->imp_connect_data, IMP_RECOV))
+                       ptlrpc_pinger_ir_up();
+               break;
         case IMP_EVENT_OCD:
                 break;
         case IMP_EVENT_DEACTIVATE:
@@ -1168,63 +1356,8 @@ static int mgc_import_event(struct obd_device *obd,
         RETURN(rc);
 }
 
-static int mgc_llog_init(struct obd_device *obd, struct obd_llog_group *olg,
-                         struct obd_device *tgt, int *index)
-{
-        struct llog_ctxt *ctxt;
-        int rc;
-        ENTRY;
-
-        LASSERT(olg == &obd->obd_olg);
-
-        rc = llog_setup(obd, olg, LLOG_CONFIG_ORIG_CTXT, tgt, 0, NULL,
-                        &llog_lvfs_ops);
-        if (rc)
-                RETURN(rc);
-
-        rc = llog_setup(obd, olg, LLOG_CONFIG_REPL_CTXT, tgt, 0, NULL,
-                        &llog_client_ops);
-        if (rc == 0) {
-                ctxt = llog_get_context(obd, LLOG_CONFIG_REPL_CTXT);
-                if (!ctxt) {
-                        ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
-                        if (ctxt)
-                                llog_cleanup(ctxt);
-                        RETURN(-ENODEV);
-                }
-                llog_initiator_connect(ctxt);
-                llog_ctxt_put(ctxt);
-        } else {
-                ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
-                if (ctxt)
-                        llog_cleanup(ctxt);
-        }
-
-        RETURN(rc);
-}
-
-static int mgc_llog_finish(struct obd_device *obd, int count)
-{
-        struct llog_ctxt *ctxt;
-        int rc = 0, rc2 = 0;
-        ENTRY;
-
-        ctxt = llog_get_context(obd, LLOG_CONFIG_REPL_CTXT);
-        if (ctxt)
-                rc = llog_cleanup(ctxt);
-
-        ctxt = llog_get_context(obd, LLOG_CONFIG_ORIG_CTXT);
-        if (ctxt)
-                rc2 = llog_cleanup(ctxt);
-
-        if (!rc)
-                rc = rc2;
-
-        RETURN(rc);
-}
-
 enum {
-        CONFIG_READ_NRPAGES_INIT = 1 << (20 - CFS_PAGE_SHIFT),
+       CONFIG_READ_NRPAGES_INIT = 1 << (20 - PAGE_CACHE_SHIFT),
         CONFIG_READ_NRPAGES      = 4
 };
 
@@ -1250,27 +1383,34 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
         LASSERT(cfg->cfg_instance != NULL);
         LASSERT(cfg->cfg_sb == cfg->cfg_instance);
 
-        OBD_ALLOC(inst, CFS_PAGE_SIZE);
-        if (inst == NULL)
-                RETURN(-ENOMEM);
+       OBD_ALLOC(inst, PAGE_CACHE_SIZE);
+       if (inst == NULL)
+               RETURN(-ENOMEM);
 
        if (!IS_SERVER(lsi)) {
-                pos = sprintf(inst, "%p", cfg->cfg_instance);
+               pos = snprintf(inst, PAGE_CACHE_SIZE, "%p", cfg->cfg_instance);
+               if (pos >= PAGE_CACHE_SIZE) {
+                       OBD_FREE(inst, PAGE_CACHE_SIZE);
+                       return -E2BIG;
+               }
         } else {
                LASSERT(IS_MDT(lsi));
-               rc = server_name2svname(lsi->lsi_svname, inst, NULL);
-               if (rc)
+               rc = server_name2svname(lsi->lsi_svname, inst, NULL,
+                                       PAGE_CACHE_SIZE);
+               if (rc) {
+                       OBD_FREE(inst, PAGE_CACHE_SIZE);
                        RETURN(-EINVAL);
+               }
                pos = strlen(inst);
         }
 
         ++pos;
         buf   = inst + pos;
-        bufsz = CFS_PAGE_SIZE - pos;
+       bufsz = PAGE_CACHE_SIZE - pos;
 
         while (datalen > 0) {
                 int   entry_len = sizeof(*entry);
-                int   is_ost;
+               int   is_ost, i;
                 struct obd_device *obd;
                 char *obdname;
                 char *cname;
@@ -1298,7 +1438,7 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
                /* Keep this swab for normal mixed endian handling. LU-1644 */
                if (mne_swab)
                        lustre_swab_mgs_nidtbl_entry(entry);
-               if (entry->mne_length > CFS_PAGE_SIZE) {
+               if (entry->mne_length > PAGE_CACHE_SIZE) {
                        CERROR("MNE too large (%u)\n", entry->mne_length);
                        break;
                }
@@ -1357,7 +1497,7 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
                 if (obd == NULL) {
                         CDEBUG(D_INFO, "mgc %s: cannot find obdname %s\n",
                                mgc->obd_name, obdname);
-
+                       rc = 0;
                         /* this is a safe race, when the ost is starting up...*/
                         continue;
                 }
@@ -1368,11 +1508,26 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
                 pos += sprintf(params, "%s.import=%s", cname, "connection=");
                 uuid = buf + pos;
 
-                /* TODO: iterate all nids to find one */
-                /* find uuid by nid */
-                rc = client_import_find_conn(obd->u.cli.cl_import,
-                                             entry->u.nids[0],
-                                             (struct obd_uuid *)uuid);
+               down_read(&obd->u.cli.cl_sem);
+               if (obd->u.cli.cl_import == NULL) {
+                       /* client does not connect to the OST yet */
+                       up_read(&obd->u.cli.cl_sem);
+                       rc = 0;
+                       continue;
+               }
+
+               /* iterate all nids to find one */
+               /* find uuid by nid */
+               rc = -ENOENT;
+               for (i = 0; i < entry->mne_nid_count; i++) {
+                       rc = client_import_find_conn(obd->u.cli.cl_import,
+                                                    entry->u.nids[i],
+                                                    (struct obd_uuid *)uuid);
+                       if (rc == 0)
+                               break;
+               }
+
+               up_read(&obd->u.cli.cl_sem);
                 if (rc < 0) {
                         CERROR("mgc: cannot find uuid by nid %s\n",
                                libcfs_nid2str(entry->u.nids[0]));
@@ -1388,12 +1543,11 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
 
                 lustre_cfg_bufs_set_string(&bufs, 1, params);
 
-                rc = -ENOMEM;
-                lcfg = lustre_cfg_new(LCFG_PARAM, &bufs);
-                if (lcfg == NULL) {
-                        CERROR("mgc: cannot allocate memory\n");
-                        break;
-                }
+               lcfg = lustre_cfg_new(LCFG_PARAM, &bufs);
+               if (lcfg == NULL) {
+                       rc = -ENOMEM;
+                       break;
+               }
 
                 CDEBUG(D_INFO, "ir apply logs "LPD64"/"LPD64" for %s -> %s\n",
                        prev_version, max_version, obdname, params);
@@ -1407,30 +1561,35 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
                 /* continue, even one with error */
         }
 
-        OBD_FREE(inst, CFS_PAGE_SIZE);
+       OBD_FREE(inst, PAGE_CACHE_SIZE);
         RETURN(rc);
 }
 
 /**
  * This function is called if this client was notified for target restarting
- * by the MGS. A CONFIG_READ RPC is going to send to fetch recovery logs.
+ * by the MGS. A CONFIG_READ RPC is going to send to fetch recovery or
+ * nodemap logs.
  */
-static int mgc_process_recover_log(struct obd_device *obd,
-                                   struct config_llog_data *cld)
+static int mgc_process_recover_nodemap_log(struct obd_device *obd,
+                                          struct config_llog_data *cld)
 {
-        struct ptlrpc_request *req = NULL;
-        struct config_llog_instance *cfg = &cld->cld_cfg;
-        struct mgs_config_body *body;
-        struct mgs_config_res  *res;
-        struct ptlrpc_bulk_desc *desc;
-        cfs_page_t **pages;
-        int nrpages;
-        bool eof = true;
+       struct ptlrpc_request *req = NULL;
+       struct config_llog_instance *cfg = &cld->cld_cfg;
+       struct mgs_config_body *body;
+       struct mgs_config_res *res;
+       struct nodemap_config *new_config = NULL;
+       struct lu_nodemap *recent_nodemap = NULL;
+       struct ptlrpc_bulk_desc *desc;
+       struct page **pages;
+       __u64 config_read_offset = 0;
+       int nrpages;
+       bool eof = true;
        bool mne_swab = false;
-        int i;
-        int ealen;
-        int rc;
-        ENTRY;
+       int i;
+       int ealen;
+       int rc;
+
+       ENTRY;
 
         /* allocate buffer for bulk transfer.
          * if this is the first time for this mgs to read logs,
@@ -1439,7 +1598,7 @@ static int mgc_process_recover_log(struct obd_device *obd,
          * small and CONFIG_READ_NRPAGES will be used.
          */
         nrpages = CONFIG_READ_NRPAGES;
-        if (cfg->cfg_last_idx == 0) /* the first time */
+       if (cfg->cfg_last_idx == 0 || cld_is_nodemap(cld))
                 nrpages = CONFIG_READ_NRPAGES_INIT;
 
         OBD_ALLOC(pages, sizeof(*pages) * nrpages);
@@ -1447,417 +1606,488 @@ static int mgc_process_recover_log(struct obd_device *obd,
                 GOTO(out, rc = -ENOMEM);
 
         for (i = 0; i < nrpages; i++) {
-                pages[i] = cfs_alloc_page(CFS_ALLOC_STD);
+               pages[i] = alloc_page(GFP_KERNEL);
                 if (pages[i] == NULL)
                         GOTO(out, rc = -ENOMEM);
         }
 
 again:
-        LASSERT(cld_is_recover(cld));
-        LASSERT(cfs_mutex_is_locked(&cld->cld_lock));
-        req = ptlrpc_request_alloc(class_exp2cliimp(cld->cld_mgcexp),
-                                   &RQF_MGS_CONFIG_READ);
-        if (req == NULL)
-                GOTO(out, rc = -ENOMEM);
-
-        rc = ptlrpc_request_pack(req, LUSTRE_MGS_VERSION, MGS_CONFIG_READ);
-        if (rc)
-                GOTO(out, rc);
-
-        /* pack request */
-        body = req_capsule_client_get(&req->rq_pill, &RMF_MGS_CONFIG_BODY);
-        LASSERT(body != NULL);
-        LASSERT(sizeof(body->mcb_name) > strlen(cld->cld_logname));
-        strncpy(body->mcb_name, cld->cld_logname, sizeof(body->mcb_name));
-        body->mcb_offset = cfg->cfg_last_idx + 1;
-        body->mcb_type   = cld->cld_type;
-        body->mcb_bits   = CFS_PAGE_SHIFT;
-        body->mcb_units  = nrpages;
-
-        /* allocate bulk transfer descriptor */
-        desc = ptlrpc_prep_bulk_imp(req, nrpages, BULK_PUT_SINK,
-                                    MGS_BULK_PORTAL);
-        if (desc == NULL)
-                GOTO(out, rc = -ENOMEM);
-
-        for (i = 0; i < nrpages; i++)
-                ptlrpc_prep_bulk_page(desc, pages[i], 0, CFS_PAGE_SIZE);
+#ifdef HAVE_SERVER_SUPPORT
+       if (cld_is_nodemap(cld) && config_read_offset == 0) {
+               new_config = nodemap_config_alloc();
+               if (IS_ERR(new_config)) {
+                       rc = PTR_ERR(new_config);
+                       new_config = NULL;
+                       GOTO(out, rc);
+               }
+       }
+#endif
+       LASSERT(cld_is_recover(cld) || cld_is_nodemap(cld));
+       LASSERT(mutex_is_locked(&cld->cld_lock));
+       req = ptlrpc_request_alloc(class_exp2cliimp(cld->cld_mgcexp),
+                                  &RQF_MGS_CONFIG_READ);
+       if (req == NULL)
+               GOTO(out, rc = -ENOMEM);
+
+       rc = ptlrpc_request_pack(req, LUSTRE_MGS_VERSION, MGS_CONFIG_READ);
+       if (rc)
+               GOTO(out, rc);
 
-        ptlrpc_request_set_replen(req);
-        rc = ptlrpc_queue_wait(req);
-        if (rc)
-                GOTO(out, rc);
+       /* pack request */
+       body = req_capsule_client_get(&req->rq_pill, &RMF_MGS_CONFIG_BODY);
+       LASSERT(body != NULL);
+       LASSERT(sizeof(body->mcb_name) > strlen(cld->cld_logname));
+       if (strlcpy(body->mcb_name, cld->cld_logname, sizeof(body->mcb_name))
+           >= sizeof(body->mcb_name))
+               GOTO(out, rc = -E2BIG);
+       if (cld_is_nodemap(cld))
+               body->mcb_offset = config_read_offset;
+       else
+               body->mcb_offset = cfg->cfg_last_idx + 1;
+       body->mcb_type   = cld->cld_type;
+       body->mcb_bits   = PAGE_CACHE_SHIFT;
+       body->mcb_units  = nrpages;
+
+       /* allocate bulk transfer descriptor */
+       desc = ptlrpc_prep_bulk_imp(req, nrpages, 1,
+                                   PTLRPC_BULK_PUT_SINK | PTLRPC_BULK_BUF_KIOV,
+                                   MGS_BULK_PORTAL,
+                                   &ptlrpc_bulk_kiov_pin_ops);
+       if (desc == NULL)
+               GOTO(out, rc = -ENOMEM);
+
+       for (i = 0; i < nrpages; i++)
+               desc->bd_frag_ops->add_kiov_frag(desc, pages[i], 0,
+                                                PAGE_CACHE_SIZE);
+
+       ptlrpc_request_set_replen(req);
+       rc = ptlrpc_queue_wait(req);
+       if (rc)
+               GOTO(out, rc);
 
-        res = req_capsule_server_get(&req->rq_pill, &RMF_MGS_CONFIG_RES);
-        if (res->mcr_size < res->mcr_offset)
-                GOTO(out, rc = -EINVAL);
+       res = req_capsule_server_get(&req->rq_pill, &RMF_MGS_CONFIG_RES);
+       if (!res)
+               GOTO(out, rc = -EPROTO);
+
+       if (cld_is_nodemap(cld)) {
+               config_read_offset = res->mcr_offset;
+               eof = config_read_offset == II_END_OFF;
+       } else {
+               if (res->mcr_size < res->mcr_offset)
+                       GOTO(out, rc = -EINVAL);
+
+               /* always update the index even though it might have errors with
+                * handling the recover logs
+                */
+               cfg->cfg_last_idx = res->mcr_offset;
+               eof = res->mcr_offset == res->mcr_size;
+
+               CDEBUG(D_INFO, "Latest version "LPD64", more %d.\n",
+                      res->mcr_offset, eof == false);
+       }
 
-        /* always update the index even though it might have errors with
-         * handling the recover logs */
-        cfg->cfg_last_idx = res->mcr_offset;
-        eof = res->mcr_offset == res->mcr_size;
+       ealen = sptlrpc_cli_unwrap_bulk_read(req, req->rq_bulk, 0);
+       if (ealen < 0)
+               GOTO(out, rc = ealen);
 
-        CDEBUG(D_INFO, "Latest version "LPD64", more %d.\n",
-               res->mcr_offset, eof == false);
+       if (ealen > nrpages << PAGE_CACHE_SHIFT)
+               GOTO(out, rc = -EINVAL);
 
-        ealen = sptlrpc_cli_unwrap_bulk_read(req, req->rq_bulk, 0);
-        if (ealen < 0)
-                GOTO(out, rc = ealen);
+       if (ealen == 0) { /* no logs transferred */
+#ifdef HAVE_SERVER_SUPPORT
+               /* config changed since first read RPC */
+               if (cld_is_nodemap(cld) && config_read_offset == 0) {
+                       recent_nodemap = NULL;
+                       nodemap_config_dealloc(new_config);
+                       new_config = NULL;
 
-        if (ealen > nrpages << CFS_PAGE_SHIFT)
-                GOTO(out, rc = -EINVAL);
+                       CDEBUG(D_INFO, "nodemap config changed in transit, retrying\n");
 
-        if (ealen == 0) { /* no logs transferred */
-                if (!eof)
-                        rc = -EINVAL;
-                GOTO(out, rc);
-        }
+                       /* setting eof to false, we request config again */
+                       eof = false;
+                       GOTO(out, rc = 0);
+               }
+#endif
+               if (!eof)
+                       rc = -EINVAL;
+               GOTO(out, rc);
+       }
 
        mne_swab = !!ptlrpc_rep_need_swab(req);
-#if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(2, 6, 50, 0)
+#if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 0, 53, 0)
        /* This import flag means the server did an extra swab of IR MNE
         * records (fixed in LU-1252), reverse it here if needed. LU-1644 */
        if (unlikely(req->rq_import->imp_need_mne_swab))
                mne_swab = !mne_swab;
-#else
-#warning "LU-1644: Remove old OBD_CONNECT_MNE_SWAB fixup and exp_need_mne_swab"
 #endif
 
-        for (i = 0; i < nrpages && ealen > 0; i++) {
-                int rc2;
-                void *ptr;
-
-                ptr = cfs_kmap(pages[i]);
-                rc2 = mgc_apply_recover_logs(obd, cld, res->mcr_offset, ptr,
-                                            min_t(int, ealen, CFS_PAGE_SIZE),
-                                            mne_swab);
-                cfs_kunmap(pages[i]);
-                if (rc2 < 0) {
-                        CWARN("Process recover log %s error %d\n",
-                              cld->cld_logname, rc2);
-                        break;
-                }
+       /* When a nodemap config is received, we build a new nodemap config,
+        * with new nodemap structs. We keep track of the most recently added
+        * nodemap since the config is read ordered by nodemap_id, and so it
+        * is likely that the next record will be related. Because access to
+        * the nodemaps is single threaded until the nodemap_config is active,
+        * we don't need to reference count with recent_nodemap, though
+        * recent_nodemap should be set to NULL when the nodemap_config
+        * is either destroyed or set active.
+        */
+       for (i = 0; i < nrpages && ealen > 0; i++) {
+               int rc2;
+               union lu_page   *ptr;
+
+               ptr = kmap(pages[i]);
+               if (cld_is_nodemap(cld))
+                       rc2 = nodemap_process_idx_pages(new_config, ptr,
+                                                      &recent_nodemap);
+               else
+                       rc2 = mgc_apply_recover_logs(obd, cld, res->mcr_offset,
+                                                    ptr,
+                                                    min_t(int, ealen,
+                                                          PAGE_CACHE_SIZE),
+                                                    mne_swab);
+               kunmap(pages[i]);
+               if (rc2 < 0) {
+                       CWARN("%s: error processing %s log %s: rc = %d\n",
+                             obd->obd_name,
+                             cld_is_nodemap(cld) ? "nodemap" : "recovery",
+                             cld->cld_logname,
+                             rc2);
+                       break;
+               }
 
-                ealen -= CFS_PAGE_SIZE;
-        }
+               ealen -= PAGE_CACHE_SIZE;
+       }
 
 out:
-        if (req)
-                ptlrpc_req_finished(req);
-
-        if (rc == 0 && !eof)
-                goto again;
-
-        if (pages) {
-                for (i = 0; i < nrpages; i++) {
-                        if (pages[i] == NULL)
-                                break;
-                        cfs_free_page(pages[i]);
-                }
-                OBD_FREE(pages, sizeof(*pages) * nrpages);
-        }
-        return rc;
-}
-
-/* identical to mgs_log_is_empty */
-static int mgc_llog_is_empty(struct obd_device *obd, struct llog_ctxt *ctxt,
-                            char *name)
-{
-       struct lvfs_run_ctxt     saved;
-       struct llog_handle      *llh;
-       int                      rc = 0;
-
-       push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
-       rc = llog_create(NULL, ctxt, &llh, NULL, name);
-       if (rc == 0) {
-               llog_init_handle(NULL, llh, LLOG_F_IS_PLAIN, NULL);
-               rc = llog_get_size(llh);
-               llog_close(NULL, llh);
+       if (req) {
+               ptlrpc_req_finished(req);
+               req = NULL;
        }
-       pop_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
-       /* header is record 1 */
-       return (rc <= 1);
-}
-
-static int mgc_copy_handler(const struct lu_env *env, struct llog_handle *llh,
-                           struct llog_rec_hdr *rec, void *data)
-{
-        struct llog_rec_hdr local_rec = *rec;
-        struct llog_handle *local_llh = (struct llog_handle *)data;
-        char *cfg_buf = (char*) (rec + 1);
-        struct lustre_cfg *lcfg;
-        int rc = 0;
-        ENTRY;
 
-        /* Append all records */
-        local_rec.lrh_len -= sizeof(*rec) + sizeof(struct llog_rec_tail);
-       rc = llog_write_rec(env, local_llh, &local_rec, NULL, 0,
-                            (void *)cfg_buf, -1);
+       if (rc == 0 && !eof)
+               goto again;
 
-        lcfg = (struct lustre_cfg *)cfg_buf;
-        CDEBUG(D_INFO, "idx=%d, rc=%d, len=%d, cmd %x %s %s\n",
-               rec->lrh_index, rc, rec->lrh_len, lcfg->lcfg_command,
-               lustre_cfg_string(lcfg, 0), lustre_cfg_string(lcfg, 1));
+#ifdef HAVE_SERVER_SUPPORT
+       if (new_config != NULL) {
+               /* recent_nodemap cannot be used after set_active/dealloc */
+               if (rc == 0)
+                       nodemap_config_set_active_mgc(new_config);
+               else
+                       nodemap_config_dealloc(new_config);
+       }
+#endif
 
-        RETURN(rc);
+       if (pages) {
+               for (i = 0; i < nrpages; i++) {
+                       if (pages[i] == NULL)
+                               break;
+                       __free_page(pages[i]);
+               }
+               OBD_FREE(pages, sizeof(*pages) * nrpages);
+       }
+       return rc;
 }
 
 /* Copy a remote log locally */
-static int mgc_copy_llog(struct obd_device *obd, struct llog_ctxt *rctxt,
-                         struct llog_ctxt *lctxt, char *logname)
+static int mgc_llog_local_copy(const struct lu_env *env,
+                              struct obd_device *obd,
+                              struct llog_ctxt *rctxt,
+                              struct llog_ctxt *lctxt, char *logname)
 {
-        struct llog_handle *local_llh, *remote_llh;
-        struct obd_uuid *uuid;
-        char *temp_log;
-        int rc, rc2;
-        ENTRY;
+       char    *temp_log;
+       int      rc;
 
-        /* Write new log to a temp name, then vfs_rename over logname
-           upon successful completion. */
+       ENTRY;
 
-        OBD_ALLOC(temp_log, strlen(logname) + 1);
-        if (!temp_log)
-                RETURN(-ENOMEM);
-        sprintf(temp_log, "%sT", logname);
+       /*
+        * - copy it to backup using llog_backup()
+        * - copy remote llog to logname using llog_backup()
+        * - if failed then move bakup to logname again
+        */
 
-        /* Make sure there's no old temp log */
-       rc = llog_create(NULL, lctxt, &local_llh, NULL, temp_log);
-       if (rc)
-               GOTO(out, rc);
-       rc = llog_init_handle(NULL, local_llh, LLOG_F_IS_PLAIN, NULL);
-       if (rc)
+       OBD_ALLOC(temp_log, strlen(logname) + 2);
+       if (!temp_log)
+               RETURN(-ENOMEM);
+       sprintf(temp_log, "%sT", logname);
+
+       /* make a copy of local llog at first */
+       rc = llog_backup(env, obd, lctxt, lctxt, logname, temp_log);
+       if (rc < 0 && rc != -ENOENT)
                GOTO(out, rc);
-       rc = llog_destroy(NULL, local_llh);
-        llog_free_handle(local_llh);
-        if (rc)
-                GOTO(out, rc);
-
-        /* open local log */
-       rc = llog_create(NULL, lctxt, &local_llh, NULL, temp_log);
-        if (rc)
-                GOTO(out, rc);
-
-        /* set the log header uuid for fun */
-        OBD_ALLOC_PTR(uuid);
-        obd_str2uuid(uuid, logname);
-       rc = llog_init_handle(NULL, local_llh, LLOG_F_IS_PLAIN, uuid);
-        OBD_FREE_PTR(uuid);
-        if (rc)
-                GOTO(out_closel, rc);
-
-        /* open remote log */
-       rc = llog_create(NULL, rctxt, &remote_llh, NULL, logname);
-       if (rc)
-               GOTO(out_closel, rc);
-       rc = llog_init_handle(NULL, remote_llh, LLOG_F_IS_PLAIN, NULL);
-        if (rc)
-                GOTO(out_closer, rc);
-
-        /* Copy remote log */
-       rc = llog_process(NULL, remote_llh, mgc_copy_handler,
-                         (void *)local_llh, NULL);
-
-out_closer:
-       rc2 = llog_close(NULL, remote_llh);
-       if (!rc)
-               rc = rc2;
-out_closel:
-       rc2 = llog_close(NULL, local_llh);
-        if (!rc)
-                rc = rc2;
-
-        /* We've copied the remote log to the local temp log, now
-           replace the old local log with the temp log. */
-        if (!rc) {
-                struct client_obd *cli = &obd->u.cli;
-                LASSERT(cli);
-                LASSERT(cli->cl_mgc_configs_dir);
-                rc = lustre_rename(cli->cl_mgc_configs_dir, cli->cl_mgc_vfsmnt,
-                                   temp_log, logname);
-        }
-        CDEBUG(D_MGC, "Copied remote log %s (%d)\n", logname, rc);
+       /* copy remote llog to the local copy */
+       rc = llog_backup(env, obd, rctxt, lctxt, logname, logname);
+       if (rc == -ENOENT) {
+               /* no remote llog, delete local one too */
+               llog_erase(env, lctxt, NULL, logname);
+       } else if (rc < 0) {
+               /* error during backup, get local one back from the copy */
+               llog_backup(env, obd, lctxt, lctxt, temp_log, logname);
 out:
-        if (rc)
-                CERROR("Failed to copy remote log %s (%d)\n", logname, rc);
-        OBD_FREE(temp_log, strlen(logname) + 1);
-        RETURN(rc);
+               CERROR("%s: failed to copy remote log %s: rc = %d\n",
+                      obd->obd_name, logname, rc);
+       }
+       llog_erase(env, lctxt, NULL, temp_log);
+       OBD_FREE(temp_log, strlen(logname) + 2);
+       return rc;
 }
 
 /* local_only means it cannot get remote llogs */
 static int mgc_process_cfg_log(struct obd_device *mgc,
-                               struct config_llog_data *cld,
-                               int local_only)
+                              struct config_llog_data *cld, int local_only)
 {
-        struct llog_ctxt *ctxt, *lctxt = NULL;
-        struct client_obd *cli = &mgc->u.cli;
-        struct lvfs_run_ctxt *saved_ctxt;
-        struct lustre_sb_info *lsi = NULL;
-        int rc = 0, must_pop = 0;
-        bool sptlrpc_started = false;
-
-        ENTRY;
+       struct llog_ctxt        *ctxt, *lctxt = NULL;
+       struct client_obd       *cli = &mgc->u.cli;
+       struct lustre_sb_info   *lsi = NULL;
+       int                      rc = 0;
+       bool                     sptlrpc_started = false;
+       struct lu_env           *env;
 
-        LASSERT(cld);
-        LASSERT(cfs_mutex_is_locked(&cld->cld_lock));
+       ENTRY;
 
-        /*
-         * local copy of sptlrpc log is controlled elsewhere, don't try to
-         * read it up here.
-         */
-        if (cld_is_sptlrpc(cld) && local_only)
-                RETURN(0);
+       LASSERT(cld);
+       LASSERT(mutex_is_locked(&cld->cld_lock));
 
-        if (cld->cld_cfg.cfg_sb)
-                lsi = s2lsi(cld->cld_cfg.cfg_sb);
+       /*
+        * local copy of sptlrpc log is controlled elsewhere, don't try to
+        * read it up here.
+        */
+       if (cld_is_sptlrpc(cld) && local_only)
+               RETURN(0);
 
-        ctxt = llog_get_context(mgc, LLOG_CONFIG_REPL_CTXT);
-        if (!ctxt) {
-                CERROR("missing llog context\n");
-                RETURN(-EINVAL);
-        }
+       if (cld->cld_cfg.cfg_sb)
+               lsi = s2lsi(cld->cld_cfg.cfg_sb);
 
-        OBD_ALLOC_PTR(saved_ctxt);
-        if (saved_ctxt == NULL)
-                RETURN(-ENOMEM);
+       OBD_ALLOC_PTR(env);
+       if (env == NULL)
+               RETURN(-ENOMEM);
 
-        lctxt = llog_get_context(mgc, LLOG_CONFIG_ORIG_CTXT);
-
-        /* Copy the setup log locally if we can. Don't mess around if we're
-           running an MGS though (logs are already local). */
-       if (lctxt && lsi && IS_SERVER(lsi) &&
-            (lsi->lsi_srv_mnt == cli->cl_mgc_vfsmnt) &&
-           !IS_MGS(lsi) && lsi->lsi_srv_mnt) {
-                push_ctxt(saved_ctxt, &mgc->obd_lvfs_ctxt, NULL);
-                must_pop++;
-                if (!local_only)
-                        /* Only try to copy log if we have the lock. */
-                        rc = mgc_copy_llog(mgc, ctxt, lctxt, cld->cld_logname);
-                if (local_only || rc) {
-                        if (mgc_llog_is_empty(mgc, lctxt, cld->cld_logname)) {
-                                LCONSOLE_ERROR_MSG(0x13a, "Failed to get MGS "
-                                                   "log %s and no local copy."
-                                                   "\n", cld->cld_logname);
-                                GOTO(out_pop, rc = -ENOTCONN);
-                        }
-                        CDEBUG(D_MGC, "Failed to get MGS log %s, using local "
-                               "copy for now, will try to update later.\n",
-                               cld->cld_logname);
-                }
-                /* Now, whether we copied or not, start using the local llog.
-                   If we failed to copy, we'll start using whatever the old
-                   log has. */
-                llog_ctxt_put(ctxt);
-                ctxt = lctxt;
-                lctxt = NULL;
-        } else if (local_only) { /* no local log at client side */
-                GOTO(out_pop, rc = -EIO);
-        }
+       rc = lu_env_init(env, LCT_MG_THREAD);
+       if (rc)
+               GOTO(out_free, rc);
+
+       ctxt = llog_get_context(mgc, LLOG_CONFIG_REPL_CTXT);
+       LASSERT(ctxt);
+
+       lctxt = llog_get_context(mgc, LLOG_CONFIG_ORIG_CTXT);
+
+       /* Copy the setup log locally if we can. Don't mess around if we're
+        * running an MGS though (logs are already local). */
+       if (lctxt && lsi && IS_SERVER(lsi) && !IS_MGS(lsi) &&
+           cli->cl_mgc_configs_dir != NULL &&
+           lu2dt_dev(cli->cl_mgc_configs_dir->do_lu.lo_dev) ==
+           lsi->lsi_dt_dev) {
+               if (!local_only)
+                       /* Only try to copy log if we have the lock. */
+                       rc = mgc_llog_local_copy(env, mgc, ctxt, lctxt,
+                                                cld->cld_logname);
+               if (local_only || rc) {
+                       if (strcmp(cld->cld_logname, PARAMS_FILENAME) != 0 &&
+                           llog_is_empty(env, lctxt, cld->cld_logname)) {
+                               LCONSOLE_ERROR_MSG(0x13a, "Failed to get MGS "
+                                                  "log %s and no local copy."
+                                                  "\n", cld->cld_logname);
+                               GOTO(out_pop, rc = -ENOENT);
+                       }
+                       CDEBUG(D_MGC, "Failed to get MGS log %s, using local "
+                              "copy for now, will try to update later.\n",
+                              cld->cld_logname);
+                       rc = 0;
+               }
+               /* Now, whether we copied or not, start using the local llog.
+                * If we failed to copy, we'll start using whatever the old
+                * log has. */
+               llog_ctxt_put(ctxt);
+               ctxt = lctxt;
+               lctxt = NULL;
+       } else {
+               if (local_only) /* no local log at client side */
+                       GOTO(out_pop, rc = -EIO);
+       }
 
-        if (cld_is_sptlrpc(cld)) {
-                sptlrpc_conf_log_update_begin(cld->cld_logname);
-                sptlrpc_started = true;
-        }
+       if (cld_is_sptlrpc(cld)) {
+               sptlrpc_conf_log_update_begin(cld->cld_logname);
+               sptlrpc_started = true;
+       }
 
-        /* logname and instance info should be the same, so use our
-           copy of the instance for the update.  The cfg_last_idx will
-           be updated here. */
-        rc = class_config_parse_llog(ctxt, cld->cld_logname, &cld->cld_cfg);
-        EXIT;
+       /* logname and instance info should be the same, so use our
+        * copy of the instance for the update.  The cfg_last_idx will
+        * be updated here. */
+       rc = class_config_parse_llog(env, ctxt, cld->cld_logname,
+                                    &cld->cld_cfg);
+       EXIT;
 
 out_pop:
-        llog_ctxt_put(ctxt);
-        if (lctxt)
-                llog_ctxt_put(lctxt);
-        if (must_pop)
-                pop_ctxt(saved_ctxt, &mgc->obd_lvfs_ctxt, NULL);
-
-        OBD_FREE_PTR(saved_ctxt);
-        /*
-         * update settings on existing OBDs. doing it inside
-         * of llog_process_lock so no device is attaching/detaching
-         * in parallel.
-         * the logname must be <fsname>-sptlrpc
-         */
-        if (sptlrpc_started) {
-                LASSERT(cld_is_sptlrpc(cld));
-                sptlrpc_conf_log_update_end(cld->cld_logname);
-                class_notify_sptlrpc_conf(cld->cld_logname,
-                                          strlen(cld->cld_logname) -
-                                          strlen("-sptlrpc"));
-        }
+       __llog_ctxt_put(env, ctxt);
+       if (lctxt)
+               __llog_ctxt_put(env, lctxt);
+
+       /*
+        * update settings on existing OBDs. doing it inside
+        * of llog_process_lock so no device is attaching/detaching
+        * in parallel.
+        * the logname must be <fsname>-sptlrpc
+        */
+       if (sptlrpc_started) {
+               LASSERT(cld_is_sptlrpc(cld));
+               sptlrpc_conf_log_update_end(cld->cld_logname);
+               class_notify_sptlrpc_conf(cld->cld_logname,
+                                         strlen(cld->cld_logname) -
+                                         strlen("-sptlrpc"));
+       }
 
-        RETURN(rc);
+       lu_env_fini(env);
+out_free:
+       OBD_FREE_PTR(env);
+       return rc;
 }
 
-/** Get a config log from the MGS and process it.
- * This func is called for both clients and servers.
- * Copy the log locally before parsing it if appropriate (non-MGS server)
+static bool mgc_import_in_recovery(struct obd_import *imp)
+{
+       bool in_recovery = true;
+
+       spin_lock(&imp->imp_lock);
+       if (imp->imp_state == LUSTRE_IMP_FULL ||
+           imp->imp_state == LUSTRE_IMP_CLOSED)
+               in_recovery = false;
+       spin_unlock(&imp->imp_lock);
+
+       return in_recovery;
+}
+
+/**
+ * Get a configuration log from the MGS and process it.
+ *
+ * This function is called for both clients and servers to process the
+ * configuration log from the MGS.  The MGC enqueues a DLM lock on the
+ * log from the MGS, and if the lock gets revoked the MGC will be notified
+ * by the lock cancellation callback that the config log has changed,
+ * and will enqueue another MGS lock on it, and then continue processing
+ * the new additions to the end of the log.
+ *
+ * Since the MGC import is not replayable, if the import is being evicted
+ * (rcl == -ESHUTDOWN, \see ptlrpc_import_delay_req()), retry to process
+ * the log until recovery is finished or the import is closed.
+ *
+ * Make a local copy of the log before parsing it if appropriate (non-MGS
+ * server) so that the server can start even when the MGS is down.
+ *
+ * There shouldn't be multiple processes running process_log at once --
+ * sounds like badness.  It actually might be fine, as long as they're not
+ * trying to update from the same log simultaneously, in which case we
+ * should use a per-log semaphore instead of cld_lock.
+ *
+ * \param[in] mgc      MGC device by which to fetch the configuration log
+ * \param[in] cld      log processing state (stored in lock callback data)
+ *
+ * \retval             0 on success
+ * \retval             negative errno on failure
  */
 int mgc_process_log(struct obd_device *mgc, struct config_llog_data *cld)
 {
         struct lustre_handle lockh = { 0 };
-        int rc = 0, rcl, flags = LDLM_FL_NO_LRU;
+       __u64 flags = LDLM_FL_NO_LRU;
+       int rc = 0, rcl;
+       bool retry = false;
         ENTRY;
 
-        LASSERT(cld);
+       LASSERT(cld != NULL);
 
         /* I don't want multiple processes running process_log at once --
            sounds like badness.  It actually might be fine, as long as
            we're not trying to update from the same log
            simultaneously (in which case we should use a per-log sem.) */
-        cfs_mutex_lock(&cld->cld_lock);
-        if (cld->cld_stopping) {
-                cfs_mutex_unlock(&cld->cld_lock);
+restart:
+       mutex_lock(&cld->cld_lock);
+       if (cld->cld_stopping) {
+               mutex_unlock(&cld->cld_lock);
                 RETURN(0);
         }
 
         OBD_FAIL_TIMEOUT(OBD_FAIL_MGC_PAUSE_PROCESS_LOG, 20);
 
-        CDEBUG(D_MGC, "Process log %s:%p from %d\n", cld->cld_logname,
-               cld->cld_cfg.cfg_instance, cld->cld_cfg.cfg_last_idx + 1);
-
-        /* Get the cfg lock on the llog */
-        rcl = mgc_enqueue(mgc->u.cli.cl_mgc_mgsexp, NULL, LDLM_PLAIN, NULL,
-                          LCK_CR, &flags, NULL, NULL, NULL,
-                          cld, 0, NULL, &lockh);
-        if (rcl == 0) {
-                /* Get the cld, it will be released in mgc_blocking_ast. */
-                config_log_get(cld);
-                rc = ldlm_lock_set_data(&lockh, (void *)cld);
-                LASSERT(rc == 0);
-        } else {
-                CDEBUG(D_MGC, "Can't get cfg lock: %d\n", rcl);
+       CDEBUG(D_MGC, "Process log %s:%p from %d\n", cld->cld_logname,
+              cld->cld_cfg.cfg_instance, cld->cld_cfg.cfg_last_idx + 1);
+
+       /* Get the cfg lock on the llog */
+       rcl = mgc_enqueue(mgc->u.cli.cl_mgc_mgsexp, LDLM_PLAIN, NULL,
+                         LCK_CR, &flags, NULL, NULL, NULL,
+                         cld, 0, NULL, &lockh);
+       if (rcl == 0) {
+               /* Get the cld, it will be released in mgc_blocking_ast. */
+               config_log_get(cld);
+               rc = ldlm_lock_set_data(&lockh, (void *)cld);
+               LASSERT(rc == 0);
+       } else {
+               CDEBUG(D_MGC, "Can't get cfg lock: %d\n", rcl);
+
+               if (rcl == -ESHUTDOWN &&
+                   atomic_read(&mgc->u.cli.cl_mgc_refcount) > 0 && !retry) {
+                       struct obd_import *imp;
+                       struct l_wait_info lwi;
+                       int secs = cfs_time_seconds(obd_timeout);
+
+                       mutex_unlock(&cld->cld_lock);
+                       imp = class_exp2cliimp(mgc->u.cli.cl_mgc_mgsexp);
+
+                       /* Let's force the pinger, and wait the import to be
+                        * connected, note: since mgc import is non-replayable,
+                        * and even the import state is disconnected, it does
+                        * not mean the "recovery" is stopped, so we will keep
+                        * waitting until timeout or the import state is
+                        * FULL or closed */
+                       ptlrpc_pinger_force(imp);
+
+                       lwi = LWI_TIMEOUT(secs, NULL, NULL);
+                       l_wait_event(imp->imp_recovery_waitq,
+                                    !mgc_import_in_recovery(imp), &lwi);
+
+                       if (imp->imp_state == LUSTRE_IMP_FULL) {
+                               retry = true;
+                               goto restart;
+                       } else {
+                               mutex_lock(&cld->cld_lock);
+                               cld->cld_lostlock = 1;
+                       }
+               } else {
+                       /* mark cld_lostlock so that it will requeue
+                        * after MGC becomes available. */
+                       cld->cld_lostlock = 1;
+               }
+               /* Get extra reference, it will be put in requeue thread */
+               config_log_get(cld);
+       }
 
-                /* mark cld_lostlock so that it will requeue
-                 * after MGC becomes available. */
-                cld->cld_lostlock = 1;
-                /* Get extra reference, it will be put in requeue thread */
-                config_log_get(cld);
-        }
 
+       if (cld_is_recover(cld) || cld_is_nodemap(cld)) {
+               if (!rcl)
+                       rc = mgc_process_recover_nodemap_log(mgc, cld);
+               else if (cld_is_nodemap(cld))
+                       rc = rcl;
 
-        if (cld_is_recover(cld)) {
-                rc = 0; /* this is not a fatal error for recover log */
-                if (rcl == 0)
-                        rc = mgc_process_recover_log(mgc, cld);
-        } else {
-                rc = mgc_process_cfg_log(mgc, cld, rcl != 0);
-        }
+               if (cld_is_recover(cld) && rc) {
+                       if (!rcl) {
+                               CERROR("%s: recover log %s failed, not fatal: rc = %d\n",
+                                      mgc->obd_name, cld->cld_logname, rc);
+                               cld->cld_lostlock = 1;
+                       }
+                       rc = 0; /* this is not a fatal error for recover log */
+               }
+       } else {
+               rc = mgc_process_cfg_log(mgc, cld, rcl != 0);
+       }
 
-        CDEBUG(D_MGC, "%s: configuration from log '%s' %sed (%d).\n",
-               mgc->obd_name, cld->cld_logname, rc ? "fail" : "succeed", rc);
+       CDEBUG(D_MGC, "%s: configuration from log '%s' %sed (%d).\n",
+              mgc->obd_name, cld->cld_logname, rc ? "fail" : "succeed", rc);
 
-        cfs_mutex_unlock(&cld->cld_lock);
+       mutex_unlock(&cld->cld_lock);
 
-        /* Now drop the lock so MGS can revoke it */
-        if (!rcl) {
-                rcl = mgc_cancel(mgc->u.cli.cl_mgc_mgsexp, NULL,
-                                 LCK_CR, &lockh);
-                if (rcl)
-                        CERROR("Can't drop cfg lock: %d\n", rcl);
-        }
+       /* Now drop the lock so MGS can revoke it */
+       if (!rcl) {
+               rcl = mgc_cancel(mgc->u.cli.cl_mgc_mgsexp, LCK_CR, &lockh);
+               if (rcl)
+                       CERROR("Can't drop cfg lock: %d\n", rcl);
+       }
 
-        RETURN(rc);
+       RETURN(rc);
 }
 
 
@@ -1865,7 +2095,7 @@ int mgc_process_log(struct obd_device *mgc, struct config_llog_data *cld)
  * LCFG_LOG_START gets the config log from the MGS, processes it to start
  * any services, and adds it to the list logs to watch (follow).
  */
-static int mgc_process_config(struct obd_device *obd, obd_count len, void *buf)
+static int mgc_process_config(struct obd_device *obd, size_t len, void *buf)
 {
         struct lustre_cfg *lcfg = buf;
         struct config_llog_instance *cfg = NULL;
@@ -1936,6 +2166,19 @@ static int mgc_process_config(struct obd_device *obd, obd_count len, void *buf)
                         if (rc)
                                 CERROR("Cannot process recover llog %d\n", rc);
                 }
+
+               if (rc == 0 && cld->cld_params != NULL) {
+                       rc = mgc_process_log(obd, cld->cld_params);
+                       if (rc == -ENOENT) {
+                               CDEBUG(D_MGC, "There is no params "
+                                             "config file yet\n");
+                               rc = 0;
+                       }
+                       /* params log is optional */
+                       if (rc)
+                               CERROR("%s: can't process params llog: rc = %d\n",
+                                      obd->obd_name, rc);
+               }
                 config_log_put(cld);
 
                 break;
@@ -1959,7 +2202,7 @@ out:
         RETURN(rc);
 }
 
-struct obd_ops mgc_obd_ops = {
+static struct obd_ops mgc_obd_ops = {
         .o_owner        = THIS_MODULE,
         .o_setup        = mgc_setup,
         .o_precleanup   = mgc_precleanup,
@@ -1968,33 +2211,27 @@ struct obd_ops mgc_obd_ops = {
         .o_del_conn     = client_import_del_conn,
         .o_connect      = client_connect_import,
         .o_disconnect   = client_disconnect_export,
-        //.o_enqueue      = mgc_enqueue,
-        .o_cancel       = mgc_cancel,
-        //.o_iocontrol    = mgc_iocontrol,
         .o_set_info_async = mgc_set_info_async,
         .o_get_info       = mgc_get_info,
         .o_import_event = mgc_import_event,
-        .o_llog_init    = mgc_llog_init,
-        .o_llog_finish  = mgc_llog_finish,
         .o_process_config = mgc_process_config,
 };
 
-int __init mgc_init(void)
+static int __init mgc_init(void)
 {
-        return class_register_type(&mgc_obd_ops, NULL, NULL,
-                                   LUSTRE_MGC_NAME, NULL);
+       return class_register_type(&mgc_obd_ops, NULL, true, NULL,
+                                  LUSTRE_MGC_NAME, NULL);
 }
 
-#ifdef __KERNEL__
-static void /*__exit*/ mgc_exit(void)
+static void __exit mgc_exit(void)
 {
         class_unregister_type(LUSTRE_MGC_NAME);
 }
 
-MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
+MODULE_AUTHOR("OpenSFS, Inc. <http://www.lustre.org/>");
 MODULE_DESCRIPTION("Lustre Management Client");
+MODULE_VERSION(LUSTRE_VERSION_STRING);
 MODULE_LICENSE("GPL");
 
 module_init(mgc_init);
 module_exit(mgc_exit);
-#endif