Whamcloud - gitweb
LU-2104 recovery: keep valid obd_stale_clients during recovery
[fs/lustre-release.git] / lustre / obdclass / genops.c
index 1f9c9b1..f495084 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Whamcloud, Inc.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -46,9 +46,8 @@
 #include <obd_ost.h>
 #include <obd_class.h>
 #include <lprocfs_status.h>
-#include <class_hash.h>
 
-extern struct list_head obd_types;
+extern cfs_list_t obd_types;
 spinlock_t obd_types_lock;
 
 cfs_mem_cache_t *obd_device_cachep;
@@ -56,15 +55,17 @@ cfs_mem_cache_t *obdo_cachep;
 EXPORT_SYMBOL(obdo_cachep);
 cfs_mem_cache_t *import_cachep;
 
-struct list_head  obd_zombie_imports;
-struct list_head  obd_zombie_exports;
-spinlock_t        obd_zombie_impexp_lock;
+cfs_list_t      obd_zombie_imports;
+cfs_list_t      obd_zombie_exports;
+spinlock_t  obd_zombie_impexp_lock;
 static void obd_zombie_impexp_notify(void);
 static void obd_zombie_export_add(struct obd_export *exp);
 static void obd_zombie_import_add(struct obd_import *imp);
-static void print_export_data(struct obd_export *exp, const char *status);
+static void print_export_data(struct obd_export *exp,
+                              const char *status, int locks);
 
 int (*ptlrpc_put_connection_superhack)(struct ptlrpc_connection *c);
+EXPORT_SYMBOL(ptlrpc_put_connection_superhack);
 
 /*
  * support functions: we could use inter-module communication, but this
@@ -80,7 +81,6 @@ static struct obd_device *obd_device_alloc(void)
         }
         return obd;
 }
-EXPORT_SYMBOL(obd_device_alloc);
 
 static void obd_device_free(struct obd_device *obd)
 {
@@ -98,29 +98,37 @@ static void obd_device_free(struct obd_device *obd)
 
 struct obd_type *class_search_type(const char *name)
 {
-        struct list_head *tmp;
-        struct obd_type *type;
-
-        spin_lock(&obd_types_lock);
-        list_for_each(tmp, &obd_types) {
-                type = list_entry(tmp, struct obd_type, typ_chain);
-                if (strcmp(type->typ_name, name) == 0) {
-                        spin_unlock(&obd_types_lock);
-                        return type;
-                }
-        }
-        spin_unlock(&obd_types_lock);
-        return NULL;
+       cfs_list_t *tmp;
+       struct obd_type *type;
+
+       spin_lock(&obd_types_lock);
+       cfs_list_for_each(tmp, &obd_types) {
+               type = cfs_list_entry(tmp, struct obd_type, typ_chain);
+               if (strcmp(type->typ_name, name) == 0) {
+                       spin_unlock(&obd_types_lock);
+                       return type;
+               }
+       }
+       spin_unlock(&obd_types_lock);
+       return NULL;
 }
+EXPORT_SYMBOL(class_search_type);
 
 struct obd_type *class_get_type(const char *name)
 {
         struct obd_type *type = class_search_type(name);
 
-#ifdef CONFIG_KMOD
+#ifdef HAVE_MODULE_LOADING_SUPPORT
         if (!type) {
                 const char *modname = name;
-                if (!request_module("%s", modname)) {
+
+               if (strcmp(modname, "obdfilter") == 0)
+                       modname = "ofd";
+
+               if (!strncmp(modname, LUSTRE_MDS_NAME, strlen(LUSTRE_MDS_NAME)))
+                       modname = LUSTRE_MDT_NAME;
+
+                if (!cfs_request_module("%s", modname)) {
                         CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
                         type = class_search_type(name);
                 } else {
@@ -130,22 +138,24 @@ struct obd_type *class_get_type(const char *name)
         }
 #endif
         if (type) {
-                spin_lock(&type->obd_type_lock);
-                type->typ_refcnt++;
-                try_module_get(type->typ_dt_ops->o_owner);
-                spin_unlock(&type->obd_type_lock);
-        }
-        return type;
+               spin_lock(&type->obd_type_lock);
+               type->typ_refcnt++;
+               cfs_try_module_get(type->typ_dt_ops->o_owner);
+               spin_unlock(&type->obd_type_lock);
+       }
+       return type;
 }
+EXPORT_SYMBOL(class_get_type);
 
 void class_put_type(struct obd_type *type)
 {
-        LASSERT(type);
-        spin_lock(&type->obd_type_lock);
-        type->typ_refcnt--;
-        module_put(type->typ_dt_ops->o_owner);
-        spin_unlock(&type->obd_type_lock);
+       LASSERT(type);
+       spin_lock(&type->obd_type_lock);
+       type->typ_refcnt--;
+       cfs_module_put(type->typ_dt_ops->o_owner);
+       spin_unlock(&type->obd_type_lock);
 }
+EXPORT_SYMBOL(class_put_type);
 
 #define CLASS_MAX_NAME 1024
 
@@ -184,7 +194,7 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
         if (md_ops)
                 *(type->typ_md_ops) = *md_ops;
         strcpy(type->typ_name, name);
-        spin_lock_init(&type->obd_type_lock);
+       spin_lock_init(&type->obd_type_lock);
 
 #ifdef LPROCFS
         type->typ_procroot = lprocfs_register(type->typ_name, proc_lustre_root,
@@ -202,9 +212,9 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
                         GOTO (failed, rc);
         }
 
-        spin_lock(&obd_types_lock);
-        list_add(&type->typ_chain, &obd_types);
-        spin_unlock(&obd_types_lock);
+       spin_lock(&obd_types_lock);
+       cfs_list_add(&type->typ_chain, &obd_types);
+       spin_unlock(&obd_types_lock);
 
         RETURN (0);
 
@@ -218,6 +228,7 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
         OBD_FREE(type, sizeof(*type));
         RETURN(rc);
 }
+EXPORT_SYMBOL(class_register_type);
 
 int class_unregister_type(const char *name)
 {
@@ -238,16 +249,18 @@ int class_unregister_type(const char *name)
                 RETURN(-EBUSY);
         }
 
-        if (type->typ_procroot) {
-                lprocfs_remove(&type->typ_procroot);
-        }
+       /* we do not use type->typ_procroot as for compatibility purposes
+        * other modules can share names (i.e. lod can use lov entry). so
+        * we can't reference pointer as it can get invalided when another
+        * module removes the entry */
+       lprocfs_try_remove_proc_entry(type->typ_name, proc_lustre_root);
 
         if (type->typ_lu)
                 lu_device_type_fini(type->typ_lu);
 
-        spin_lock(&obd_types_lock);
-        list_del(&type->typ_chain);
-        spin_unlock(&obd_types_lock);
+       spin_lock(&obd_types_lock);
+       cfs_list_del(&type->typ_chain);
+       spin_unlock(&obd_types_lock);
         OBD_FREE(type->typ_name, strlen(name) + 1);
         if (type->typ_dt_ops != NULL)
                 OBD_FREE_PTR(type->typ_dt_ops);
@@ -256,6 +269,7 @@ int class_unregister_type(const char *name)
         OBD_FREE(type, sizeof(*type));
         RETURN(0);
 } /* class_unregister_type */
+EXPORT_SYMBOL(class_unregister_type);
 
 /**
  * Create a new obd device.
@@ -275,6 +289,7 @@ struct obd_device *class_newdev(const char *type_name, const char *name)
         struct obd_type *type = NULL;
         int i;
         int new_obd_minor = 0;
+        ENTRY;
 
         if (strlen(name) >= MAX_OBD_NAME) {
                 CERROR("name/uuid must be < %u bytes long\n", MAX_OBD_NAME);
@@ -288,18 +303,19 @@ struct obd_device *class_newdev(const char *type_name, const char *name)
         }
 
         newdev = obd_device_alloc();
-        if (newdev == NULL) {
-                class_put_type(type);
-                RETURN(ERR_PTR(-ENOMEM));
-        }
+       if (newdev == NULL)
+               GOTO(out_type, result = ERR_PTR(-ENOMEM));
+
         LASSERT(newdev->obd_magic == OBD_DEVICE_MAGIC);
 
-        spin_lock(&obd_dev_lock);
+       write_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
+
                 if (obd && obd->obd_name &&
                     (strcmp(name, obd->obd_name) == 0)) {
-                        CERROR("Device %s already exists, won't add\n", name);
+                        CERROR("Device %s already exists at %d, won't add\n",
+                               name, i);
                         if (result) {
                                 LASSERTF(result->obd_magic == OBD_DEVICE_MAGIC,
                                          "%p obd_magic %08x != %08x\n", result,
@@ -324,22 +340,26 @@ struct obd_device *class_newdev(const char *type_name, const char *name)
                         obd_devs[i] = result;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+       write_unlock(&obd_dev_lock);
 
         if (result == NULL && i >= class_devno_max()) {
                 CERROR("all %u OBD devices used, increase MAX_OBD_DEVICES\n",
                        class_devno_max());
-                result = ERR_PTR(-EOVERFLOW);
+               GOTO(out, result = ERR_PTR(-EOVERFLOW));
         }
 
-        if (IS_ERR(result)) {
-                obd_device_free(newdev);
-                class_put_type(type);
-        } else {
-                CDEBUG(D_IOCTL, "Adding new device %s (%p)\n",
-                       result->obd_name, result);
-        }
-        return result;
+       if (IS_ERR(result))
+               GOTO(out, result);
+
+       CDEBUG(D_IOCTL, "Adding new device %s (%p)\n",
+              result->obd_name, result);
+
+       RETURN(result);
+out:
+       obd_device_free(newdev);
+out_type:
+       class_put_type(type);
+       return result;
 }
 
 void class_release_dev(struct obd_device *obd)
@@ -352,12 +372,12 @@ void class_release_dev(struct obd_device *obd)
                  obd, obd->obd_minor, obd_devs[obd->obd_minor]);
         LASSERT(obd_type != NULL);
 
-        CDEBUG(D_INFO, "Release obd device %s obd_type name =%s\n",
-               obd->obd_name,obd->obd_type->typ_name);
+        CDEBUG(D_INFO, "Release obd device %s at %d obd_type name =%s\n",
+               obd->obd_name, obd->obd_minor, obd->obd_type->typ_name);
 
-        spin_lock(&obd_dev_lock);
+       write_lock(&obd_dev_lock);
         obd_devs[obd->obd_minor] = NULL;
-        spin_unlock(&obd_dev_lock);
+       write_unlock(&obd_dev_lock);
         obd_device_free(obd);
 
         class_put_type(obd_type);
@@ -370,24 +390,26 @@ int class_name2dev(const char *name)
         if (!name)
                 return -1;
 
-        spin_lock(&obd_dev_lock);
+       read_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
+
                 if (obd && obd->obd_name && strcmp(name, obd->obd_name) == 0) {
                         /* Make sure we finished attaching before we give
                            out any references */
                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
                         if (obd->obd_attached) {
-                                spin_unlock(&obd_dev_lock);
+                               read_unlock(&obd_dev_lock);
                                 return i;
                         }
                         break;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+       read_unlock(&obd_dev_lock);
 
         return -1;
 }
+EXPORT_SYMBOL(class_name2dev);
 
 struct obd_device *class_name2obd(const char *name)
 {
@@ -397,24 +419,27 @@ struct obd_device *class_name2obd(const char *name)
                 return NULL;
         return class_num2obd(dev);
 }
+EXPORT_SYMBOL(class_name2obd);
 
 int class_uuid2dev(struct obd_uuid *uuid)
 {
         int i;
 
-        spin_lock(&obd_dev_lock);
+       read_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
+
                 if (obd && obd_uuid_equals(uuid, &obd->obd_uuid)) {
                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
-                        spin_unlock(&obd_dev_lock);
+                       read_unlock(&obd_dev_lock);
                         return i;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+       read_unlock(&obd_dev_lock);
 
         return -1;
 }
+EXPORT_SYMBOL(class_uuid2dev);
 
 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 {
@@ -423,6 +448,7 @@ struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
                 return NULL;
         return class_num2obd(dev);
 }
+EXPORT_SYMBOL(class_uuid2obd);
 
 /**
  * Get obd device from ::obd_devs[]
@@ -451,15 +477,17 @@ struct obd_device *class_num2obd(int num)
 
         return obd;
 }
+EXPORT_SYMBOL(class_num2obd);
 
 void class_obd_list(void)
 {
         char *status;
         int i;
 
-        spin_lock(&obd_dev_lock);
+       read_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
+
                 if (obd == NULL)
                         continue;
                 if (obd->obd_stopping)
@@ -473,9 +501,9 @@ void class_obd_list(void)
                 LCONSOLE(D_CONFIG, "%3d %s %s %s %s %d\n",
                          i, status, obd->obd_type->typ_name,
                          obd->obd_name, obd->obd_uuid.uuid,
-                         atomic_read(&obd->obd_refcount));
+                         cfs_atomic_read(&obd->obd_refcount));
         }
-        spin_unlock(&obd_dev_lock);
+       read_unlock(&obd_dev_lock);
         return;
 }
 
@@ -488,9 +516,10 @@ struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 {
         int i;
 
-        spin_lock(&obd_dev_lock);
+       read_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
+
                 if (obd == NULL)
                         continue;
                 if ((strncmp(obd->obd_type->typ_name, typ_name,
@@ -499,15 +528,16 @@ struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
                                             &obd->u.cli.cl_target_uuid) &&
                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
                                                          &obd->obd_uuid) : 1)) {
-                                spin_unlock(&obd_dev_lock);
+                               read_unlock(&obd_dev_lock);
                                 return obd;
                         }
                 }
         }
-        spin_unlock(&obd_dev_lock);
+       read_unlock(&obd_dev_lock);
 
         return NULL;
 }
+EXPORT_SYMBOL(class_find_client_obd);
 
 /* Iterate the obd_device list looking devices have grp_uuid. Start
    searching at *next, and if a device is found, the next index to look
@@ -524,22 +554,24 @@ struct obd_device * class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
         else
                 return NULL;
 
-        spin_lock(&obd_dev_lock);
+       read_lock(&obd_dev_lock);
         for (; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
+
                 if (obd == NULL)
                         continue;
                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
                         if (next != NULL)
                                 *next = i+1;
-                        spin_unlock(&obd_dev_lock);
+                       read_unlock(&obd_dev_lock);
                         return obd;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+       read_unlock(&obd_dev_lock);
 
         return NULL;
 }
+EXPORT_SYMBOL(class_devices_in_group);
 
 /**
  * to notify sptlrpc log for \a fsname has changed, let every relevant OBD
@@ -553,7 +585,7 @@ int class_notify_sptlrpc_conf(const char *fsname, int namelen)
 
         LASSERT(namelen > 0);
 
-        spin_lock(&obd_dev_lock);
+       read_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 obd = class_num2obd(i);
 
@@ -572,15 +604,15 @@ int class_notify_sptlrpc_conf(const char *fsname, int namelen)
                         continue;
 
                 class_incref(obd, __FUNCTION__, obd);
-                spin_unlock(&obd_dev_lock);
-                rc2 = obd_set_info_async(obd->obd_self_export,
+               read_unlock(&obd_dev_lock);
+                rc2 = obd_set_info_async(NULL, obd->obd_self_export,
                                          sizeof(KEY_SPTLRPC_CONF),
                                          KEY_SPTLRPC_CONF, 0, NULL, NULL);
                 rc = rc ? rc : rc2;
                 class_decref(obd, __FUNCTION__, obd);
-                spin_lock(&obd_dev_lock);
+               read_lock(&obd_dev_lock);
         }
-        spin_unlock(&obd_dev_lock);
+       read_unlock(&obd_dev_lock);
         return rc;
 }
 EXPORT_SYMBOL(class_notify_sptlrpc_conf);
@@ -670,6 +702,7 @@ struct obd_export *class_conn2export(struct lustre_handle *conn)
         export = class_handle2object(conn->cookie);
         RETURN(export);
 }
+EXPORT_SYMBOL(class_conn2export);
 
 struct obd_device *class_exp2obd(struct obd_export *exp)
 {
@@ -677,6 +710,7 @@ struct obd_device *class_exp2obd(struct obd_export *exp)
                 return exp->exp_obd;
         return NULL;
 }
+EXPORT_SYMBOL(class_exp2obd);
 
 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 {
@@ -689,6 +723,7 @@ struct obd_device *class_conn2obd(struct lustre_handle *conn)
         }
         return NULL;
 }
+EXPORT_SYMBOL(class_conn2obd);
 
 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 {
@@ -697,6 +732,7 @@ struct obd_import *class_exp2cliimp(struct obd_export *exp)
                 return NULL;
         return obd->u.cli.cl_import;
 }
+EXPORT_SYMBOL(class_exp2cliimp);
 
 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 {
@@ -705,6 +741,7 @@ struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
                 return NULL;
         return obd->u.cli.cl_import;
 }
+EXPORT_SYMBOL(class_conn2cliimp);
 
 /* Export management functions */
 static void class_export_destroy(struct obd_export *exp)
@@ -712,21 +749,20 @@ static void class_export_destroy(struct obd_export *exp)
         struct obd_device *obd = exp->exp_obd;
         ENTRY;
 
-        LASSERT (atomic_read(&exp->exp_refcount) == 0);
+        LASSERT_ATOMIC_ZERO(&exp->exp_refcount);
+       LASSERT(obd != NULL);
 
         CDEBUG(D_IOCTL, "destroying export %p/%s for %s\n", exp,
                exp->exp_client_uuid.uuid, obd->obd_name);
 
-        LASSERT(obd != NULL);
-
         /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
         if (exp->exp_connection)
                 ptlrpc_put_connection_superhack(exp->exp_connection);
 
-        LASSERT(list_empty(&exp->exp_outstanding_replies));
-        LASSERT(list_empty(&exp->exp_uncommitted_replies));
-        LASSERT(list_empty(&exp->exp_req_replay_queue));
-        LASSERT(list_empty(&exp->exp_queued_rpc));
+        LASSERT(cfs_list_empty(&exp->exp_outstanding_replies));
+        LASSERT(cfs_list_empty(&exp->exp_uncommitted_replies));
+        LASSERT(cfs_list_empty(&exp->exp_req_replay_queue));
+        LASSERT(cfs_list_empty(&exp->exp_hp_rpcs));
         obd_destroy_export(exp);
         class_decref(obd, "export", exp);
 
@@ -739,11 +775,16 @@ static void export_handle_addref(void *export)
         class_export_get(export);
 }
 
+static struct portals_handle_ops export_handle_ops = {
+       .hop_addref = export_handle_addref,
+       .hop_free   = NULL,
+};
+
 struct obd_export *class_export_get(struct obd_export *exp)
 {
-        atomic_inc(&exp->exp_refcount);
+        cfs_atomic_inc(&exp->exp_refcount);
         CDEBUG(D_INFO, "GETting export %p : new refcount %d\n", exp,
-               atomic_read(&exp->exp_refcount));
+               cfs_atomic_read(&exp->exp_refcount));
         return exp;
 }
 EXPORT_SYMBOL(class_export_get);
@@ -751,15 +792,18 @@ EXPORT_SYMBOL(class_export_get);
 void class_export_put(struct obd_export *exp)
 {
         LASSERT(exp != NULL);
+        LASSERT_ATOMIC_GT_LT(&exp->exp_refcount, 0, LI_POISON);
         CDEBUG(D_INFO, "PUTting export %p : new refcount %d\n", exp,
-               atomic_read(&exp->exp_refcount) - 1);
-        LASSERT(atomic_read(&exp->exp_refcount) > 0);
-        LASSERT(atomic_read(&exp->exp_refcount) < 0x5a5a5a);
+               cfs_atomic_read(&exp->exp_refcount) - 1);
 
-        if (atomic_dec_and_test(&exp->exp_refcount)) {
-                LASSERT(!list_empty(&exp->exp_obd_chain));
+        if (cfs_atomic_dec_and_test(&exp->exp_refcount)) {
+                LASSERT(!cfs_list_empty(&exp->exp_obd_chain));
                 CDEBUG(D_IOCTL, "final put %p/%s\n",
                        exp, exp->exp_client_uuid.uuid);
+
+                /* release nid stat refererence */
+                lprocfs_exp_cleanup(exp);
+
                 obd_zombie_export_add(exp);
         }
 }
@@ -772,6 +816,7 @@ struct obd_export *class_new_export(struct obd_device *obd,
                                     struct obd_uuid *cluuid)
 {
         struct obd_export *export;
+        cfs_hash_t *hash = NULL;
         int rc = 0;
         ENTRY;
 
@@ -781,37 +826,49 @@ struct obd_export *class_new_export(struct obd_device *obd,
 
         export->exp_conn_cnt = 0;
         export->exp_lock_hash = NULL;
-        atomic_set(&export->exp_refcount, 2);
-        atomic_set(&export->exp_rpc_count, 0);
-        atomic_set(&export->exp_cb_count, 0);
-        atomic_set(&export->exp_locks_count, 0);
-        atomic_set(&export->exp_replay_count, 0);
-        export->exp_obd = obd;
-        CFS_INIT_LIST_HEAD(&export->exp_outstanding_replies);
-        spin_lock_init(&export->exp_uncommitted_replies_lock);
-        CFS_INIT_LIST_HEAD(&export->exp_uncommitted_replies);
-        CFS_INIT_LIST_HEAD(&export->exp_req_replay_queue);
-        CFS_INIT_LIST_HEAD(&export->exp_handle.h_link);
-        CFS_INIT_LIST_HEAD(&export->exp_queued_rpc);
-        class_handle_hash(&export->exp_handle, export_handle_addref);
-        export->exp_last_request_time = cfs_time_current_sec();
-        spin_lock_init(&export->exp_lock);
-        INIT_HLIST_NODE(&export->exp_uuid_hash);
-        INIT_HLIST_NODE(&export->exp_nid_hash);
-
-        export->exp_sp_peer = LUSTRE_SP_ANY;
-        export->exp_flvr.sf_rpc = SPTLRPC_FLVR_INVALID;
-        export->exp_client_uuid = *cluuid;
-        obd_init_export(export);
-
-        spin_lock(&obd->obd_dev_lock);
-         /* shouldn't happen, but might race */
-        if (obd->obd_stopping)
-                GOTO(exit_err, rc = -ENODEV);
+       export->exp_flock_hash = NULL;
+        cfs_atomic_set(&export->exp_refcount, 2);
+        cfs_atomic_set(&export->exp_rpc_count, 0);
+        cfs_atomic_set(&export->exp_cb_count, 0);
+        cfs_atomic_set(&export->exp_locks_count, 0);
+#if LUSTRE_TRACKS_LOCK_EXP_REFS
+        CFS_INIT_LIST_HEAD(&export->exp_locks_list);
+       spin_lock_init(&export->exp_locks_list_guard);
+#endif
+       cfs_atomic_set(&export->exp_replay_count, 0);
+       export->exp_obd = obd;
+       CFS_INIT_LIST_HEAD(&export->exp_outstanding_replies);
+       spin_lock_init(&export->exp_uncommitted_replies_lock);
+       CFS_INIT_LIST_HEAD(&export->exp_uncommitted_replies);
+       CFS_INIT_LIST_HEAD(&export->exp_req_replay_queue);
+       CFS_INIT_LIST_HEAD(&export->exp_handle.h_link);
+       CFS_INIT_LIST_HEAD(&export->exp_hp_rpcs);
+       class_handle_hash(&export->exp_handle, &export_handle_ops);
+       export->exp_last_request_time = cfs_time_current_sec();
+       spin_lock_init(&export->exp_lock);
+       spin_lock_init(&export->exp_rpc_lock);
+       CFS_INIT_HLIST_NODE(&export->exp_uuid_hash);
+       CFS_INIT_HLIST_NODE(&export->exp_nid_hash);
+       spin_lock_init(&export->exp_bl_list_lock);
+       CFS_INIT_LIST_HEAD(&export->exp_bl_list);
+
+       export->exp_sp_peer = LUSTRE_SP_ANY;
+       export->exp_flvr.sf_rpc = SPTLRPC_FLVR_INVALID;
+       export->exp_client_uuid = *cluuid;
+       obd_init_export(export);
+
+       spin_lock(&obd->obd_dev_lock);
+       /* shouldn't happen, but might race */
+       if (obd->obd_stopping)
+               GOTO(exit_unlock, rc = -ENODEV);
+
+       hash = cfs_hash_getref(obd->obd_uuid_hash);
+       if (hash == NULL)
+               GOTO(exit_unlock, rc = -ENODEV);
+       spin_unlock(&obd->obd_dev_lock);
 
         if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
-                rc = lustre_hash_add_unique(obd->obd_uuid_hash, cluuid,
-                                            &export->exp_uuid_hash);
+                rc = cfs_hash_add_unique(hash, cluuid, &export->exp_uuid_hash);
                 if (rc != 0) {
                         LCONSOLE_WARN("%s: denying duplicate export for %s, %d\n",
                                       obd->obd_name, cluuid->uuid, rc);
@@ -819,18 +876,28 @@ struct obd_export *class_new_export(struct obd_device *obd,
                 }
         }
 
+       spin_lock(&obd->obd_dev_lock);
+        if (obd->obd_stopping) {
+                cfs_hash_del(hash, cluuid, &export->exp_uuid_hash);
+                GOTO(exit_unlock, rc = -ENODEV);
+        }
+
         class_incref(obd, "export", export);
-        list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
-        list_add_tail(&export->exp_obd_chain_timed,
-                      &export->exp_obd->obd_exports_timed);
+        cfs_list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
+        cfs_list_add_tail(&export->exp_obd_chain_timed,
+                          &export->exp_obd->obd_exports_timed);
         export->exp_obd->obd_num_exports++;
-        spin_unlock(&obd->obd_dev_lock);
-        RETURN(export);
+       spin_unlock(&obd->obd_dev_lock);
+       cfs_hash_putref(hash);
+       RETURN(export);
 
+exit_unlock:
+       spin_unlock(&obd->obd_dev_lock);
 exit_err:
-        spin_unlock(&obd->obd_dev_lock);
+        if (hash)
+                cfs_hash_putref(hash);
         class_handle_unhash(&export->exp_handle);
-        LASSERT(hlist_unhashed(&export->exp_uuid_hash));
+        LASSERT(cfs_hlist_unhashed(&export->exp_uuid_hash));
         obd_destroy_export(export);
         OBD_FREE_PTR(export);
         return ERR_PTR(rc);
@@ -839,20 +906,20 @@ EXPORT_SYMBOL(class_new_export);
 
 void class_unlink_export(struct obd_export *exp)
 {
-        class_handle_unhash(&exp->exp_handle);
-
-        spin_lock(&exp->exp_obd->obd_dev_lock);
-        /* delete an uuid-export hashitem from hashtables */
-        if (!hlist_unhashed(&exp->exp_uuid_hash))
-                lustre_hash_del(exp->exp_obd->obd_uuid_hash,
-                                &exp->exp_client_uuid,
-                                &exp->exp_uuid_hash);
-
-        list_move(&exp->exp_obd_chain, &exp->exp_obd->obd_unlinked_exports);
-        list_del_init(&exp->exp_obd_chain_timed);
-        exp->exp_obd->obd_num_exports--;
-        spin_unlock(&exp->exp_obd->obd_dev_lock);
-        class_export_put(exp);
+       class_handle_unhash(&exp->exp_handle);
+
+       spin_lock(&exp->exp_obd->obd_dev_lock);
+       /* delete an uuid-export hashitem from hashtables */
+       if (!cfs_hlist_unhashed(&exp->exp_uuid_hash))
+               cfs_hash_del(exp->exp_obd->obd_uuid_hash,
+                            &exp->exp_client_uuid,
+                            &exp->exp_uuid_hash);
+
+       cfs_list_move(&exp->exp_obd_chain, &exp->exp_obd->obd_unlinked_exports);
+       cfs_list_del_init(&exp->exp_obd_chain_timed);
+       exp->exp_obd->obd_num_exports--;
+       spin_unlock(&exp->exp_obd->obd_dev_lock);
+       class_export_put(exp);
 }
 EXPORT_SYMBOL(class_unlink_export);
 
@@ -864,16 +931,16 @@ void class_import_destroy(struct obd_import *imp)
         CDEBUG(D_IOCTL, "destroying import %p for %s\n", imp,
                 imp->imp_obd->obd_name);
 
-        LASSERT(atomic_read(&imp->imp_refcount) == 0);
+        LASSERT_ATOMIC_ZERO(&imp->imp_refcount);
 
         ptlrpc_put_connection_superhack(imp->imp_connection);
 
-        while (!list_empty(&imp->imp_conn_list)) {
+        while (!cfs_list_empty(&imp->imp_conn_list)) {
                 struct obd_import_conn *imp_conn;
 
-                imp_conn = list_entry(imp->imp_conn_list.next,
-                                      struct obd_import_conn, oic_item);
-                list_del_init(&imp_conn->oic_item);
+                imp_conn = cfs_list_entry(imp->imp_conn_list.next,
+                                          struct obd_import_conn, oic_item);
+                cfs_list_del_init(&imp_conn->oic_item);
                 ptlrpc_put_connection_superhack(imp_conn->oic_conn);
                 OBD_FREE(imp_conn, sizeof(*imp_conn));
         }
@@ -889,13 +956,16 @@ static void import_handle_addref(void *import)
         class_import_get(import);
 }
 
+static struct portals_handle_ops import_handle_ops = {
+       .hop_addref = import_handle_addref,
+       .hop_free   = NULL,
+};
+
 struct obd_import *class_import_get(struct obd_import *import)
 {
-        LASSERT(atomic_read(&import->imp_refcount) >= 0);
-        LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
-        atomic_inc(&import->imp_refcount);
+        cfs_atomic_inc(&import->imp_refcount);
         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", import,
-               atomic_read(&import->imp_refcount),
+               cfs_atomic_read(&import->imp_refcount),
                import->imp_obd->obd_name);
         return import;
 }
@@ -905,20 +975,21 @@ void class_import_put(struct obd_import *imp)
 {
         ENTRY;
 
-        LASSERT(atomic_read(&imp->imp_refcount) > 0);
-        LASSERT(atomic_read(&imp->imp_refcount) < 0x5a5a5a);
-        LASSERT(list_empty(&imp->imp_zombie_chain));
+        LASSERT(cfs_list_empty(&imp->imp_zombie_chain));
+        LASSERT_ATOMIC_GT_LT(&imp->imp_refcount, 0, LI_POISON);
 
         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", imp,
-               atomic_read(&imp->imp_refcount) - 1,
+               cfs_atomic_read(&imp->imp_refcount) - 1,
                imp->imp_obd->obd_name);
 
-        if (atomic_dec_and_test(&imp->imp_refcount)) {
+        if (cfs_atomic_dec_and_test(&imp->imp_refcount)) {
                 CDEBUG(D_INFO, "final put import %p\n", imp);
                 obd_zombie_import_add(imp);
         }
 
-        EXIT;
+       /* catch possible import put race */
+       LASSERT_ATOMIC_GE_LT(&imp->imp_refcount, 0, LI_POISON);
+       EXIT;
 }
 EXPORT_SYMBOL(class_import_put);
 
@@ -946,21 +1017,21 @@ struct obd_import *class_new_import(struct obd_device *obd)
         CFS_INIT_LIST_HEAD(&imp->imp_replay_list);
         CFS_INIT_LIST_HEAD(&imp->imp_sending_list);
         CFS_INIT_LIST_HEAD(&imp->imp_delayed_list);
-        spin_lock_init(&imp->imp_lock);
-        imp->imp_last_success_conn = 0;
-        imp->imp_state = LUSTRE_IMP_NEW;
-        imp->imp_obd = class_incref(obd, "import", imp);
-        sema_init(&imp->imp_sec_mutex, 1);
+       spin_lock_init(&imp->imp_lock);
+       imp->imp_last_success_conn = 0;
+       imp->imp_state = LUSTRE_IMP_NEW;
+       imp->imp_obd = class_incref(obd, "import", imp);
+       mutex_init(&imp->imp_sec_mutex);
         cfs_waitq_init(&imp->imp_recovery_waitq);
 
-        atomic_set(&imp->imp_refcount, 2);
-        atomic_set(&imp->imp_unregistering, 0);
-        atomic_set(&imp->imp_inflight, 0);
-        atomic_set(&imp->imp_replay_inflight, 0);
-        atomic_set(&imp->imp_inval_count, 0);
+        cfs_atomic_set(&imp->imp_refcount, 2);
+        cfs_atomic_set(&imp->imp_unregistering, 0);
+        cfs_atomic_set(&imp->imp_inflight, 0);
+        cfs_atomic_set(&imp->imp_replay_inflight, 0);
+        cfs_atomic_set(&imp->imp_inval_count, 0);
         CFS_INIT_LIST_HEAD(&imp->imp_conn_list);
         CFS_INIT_LIST_HEAD(&imp->imp_handle.h_link);
-        class_handle_hash(&imp->imp_handle, import_handle_addref);
+       class_handle_hash(&imp->imp_handle, &import_handle_ops);
         init_imp_at(&imp->imp_at);
 
         /* the default magic is V2, will be used in connect RPC, and
@@ -973,18 +1044,61 @@ EXPORT_SYMBOL(class_new_import);
 
 void class_destroy_import(struct obd_import *import)
 {
-        LASSERT(import != NULL);
-        LASSERT(import != LP_POISON);
+       LASSERT(import != NULL);
+       LASSERT(import != LP_POISON);
 
-        class_handle_unhash(&import->imp_handle);
+       class_handle_unhash(&import->imp_handle);
 
-        spin_lock(&import->imp_lock);
-        import->imp_generation++;
-        spin_unlock(&import->imp_lock);
-        class_import_put(import);
+       spin_lock(&import->imp_lock);
+       import->imp_generation++;
+       spin_unlock(&import->imp_lock);
+       class_import_put(import);
 }
 EXPORT_SYMBOL(class_destroy_import);
 
+#if LUSTRE_TRACKS_LOCK_EXP_REFS
+
+void __class_export_add_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
+{
+       spin_lock(&exp->exp_locks_list_guard);
+
+        LASSERT(lock->l_exp_refs_nr >= 0);
+
+        if (lock->l_exp_refs_target != NULL &&
+            lock->l_exp_refs_target != exp) {
+                LCONSOLE_WARN("setting export %p for lock %p which already has export %p\n",
+                              exp, lock, lock->l_exp_refs_target);
+        }
+        if ((lock->l_exp_refs_nr ++) == 0) {
+                cfs_list_add(&lock->l_exp_refs_link, &exp->exp_locks_list);
+                lock->l_exp_refs_target = exp;
+        }
+        CDEBUG(D_INFO, "lock = %p, export = %p, refs = %u\n",
+               lock, exp, lock->l_exp_refs_nr);
+       spin_unlock(&exp->exp_locks_list_guard);
+}
+EXPORT_SYMBOL(__class_export_add_lock_ref);
+
+void __class_export_del_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
+{
+       spin_lock(&exp->exp_locks_list_guard);
+        LASSERT(lock->l_exp_refs_nr > 0);
+        if (lock->l_exp_refs_target != exp) {
+                LCONSOLE_WARN("lock %p, "
+                              "mismatching export pointers: %p, %p\n",
+                              lock, lock->l_exp_refs_target, exp);
+        }
+        if (-- lock->l_exp_refs_nr == 0) {
+                cfs_list_del_init(&lock->l_exp_refs_link);
+                lock->l_exp_refs_target = NULL;
+        }
+        CDEBUG(D_INFO, "lock = %p, export = %p, refs = %u\n",
+               lock, exp, lock->l_exp_refs_nr);
+       spin_unlock(&exp->exp_locks_list_guard);
+}
+EXPORT_SYMBOL(__class_export_del_lock_ref);
+#endif
+
 /* A connection defines an export context in which preallocation can
    be managed. This releases the export pointer reference, and returns
    the export handle, so the export refcount is 1 when this function
@@ -1014,35 +1128,44 @@ EXPORT_SYMBOL(class_connect);
 /* if export is involved in recovery then clean up related things */
 void class_export_recovery_cleanup(struct obd_export *exp)
 {
-        struct obd_device *obd = exp->exp_obd;
-
-        spin_lock_bh(&obd->obd_processing_task_lock);
-        if (exp->exp_delayed)
-                obd->obd_delayed_clients--;
-        if (obd->obd_recovering && exp->exp_in_recovery) {
-                spin_lock(&exp->exp_lock);
-                exp->exp_in_recovery = 0;
-                spin_unlock(&exp->exp_lock);
-                LASSERT(obd->obd_connected_clients);
-                obd->obd_connected_clients--;
-        }
-        /** Cleanup req replay fields */
-        if (exp->exp_req_replay_needed) {
-                spin_lock(&exp->exp_lock);
-                exp->exp_req_replay_needed = 0;
-                spin_unlock(&exp->exp_lock);
-                LASSERT(atomic_read(&obd->obd_req_replay_clients));
-                atomic_dec(&obd->obd_req_replay_clients);
-        }
-        /** Cleanup lock replay data */
-        if (exp->exp_lock_replay_needed) {
-                spin_lock(&exp->exp_lock);
-                exp->exp_lock_replay_needed = 0;
-                spin_unlock(&exp->exp_lock);
-                LASSERT(atomic_read(&obd->obd_lock_replay_clients));
-                atomic_dec(&obd->obd_lock_replay_clients);
-        }
-        spin_unlock_bh(&obd->obd_processing_task_lock);
+       struct obd_device *obd = exp->exp_obd;
+
+       spin_lock(&obd->obd_recovery_task_lock);
+       if (exp->exp_delayed)
+               obd->obd_delayed_clients--;
+       if (obd->obd_recovering) {
+               if (exp->exp_in_recovery) {
+                       spin_lock(&exp->exp_lock);
+                       exp->exp_in_recovery = 0;
+                       spin_unlock(&exp->exp_lock);
+                       LASSERT_ATOMIC_POS(&obd->obd_connected_clients);
+                       cfs_atomic_dec(&obd->obd_connected_clients);
+               }
+
+               /* if called during recovery then should update
+                * obd_stale_clients counter,
+                * lightweight exports are not counted */
+               if (exp->exp_failed &&
+                   (exp->exp_connect_flags & OBD_CONNECT_LIGHTWEIGHT) == 0)
+                       exp->exp_obd->obd_stale_clients++;
+       }
+       spin_unlock(&obd->obd_recovery_task_lock);
+       /** Cleanup req replay fields */
+       if (exp->exp_req_replay_needed) {
+               spin_lock(&exp->exp_lock);
+               exp->exp_req_replay_needed = 0;
+               spin_unlock(&exp->exp_lock);
+               LASSERT(cfs_atomic_read(&obd->obd_req_replay_clients));
+               cfs_atomic_dec(&obd->obd_req_replay_clients);
+       }
+       /** Cleanup lock replay data */
+       if (exp->exp_lock_replay_needed) {
+               spin_lock(&exp->exp_lock);
+               exp->exp_lock_replay_needed = 0;
+               spin_unlock(&exp->exp_lock);
+               LASSERT(cfs_atomic_read(&obd->obd_lock_replay_clients));
+               cfs_atomic_dec(&obd->obd_lock_replay_clients);
+       }
 }
 
 /* This function removes 1-3 references from the export:
@@ -1057,31 +1180,30 @@ int class_disconnect(struct obd_export *export)
         ENTRY;
 
         if (export == NULL) {
-                fixme();
-                CDEBUG(D_IOCTL, "attempting to free NULL export %p\n", export);
+                CWARN("attempting to free NULL export %p\n", export);
                 RETURN(-EINVAL);
         }
 
-        spin_lock(&export->exp_lock);
-        already_disconnected = export->exp_disconnected;
-        export->exp_disconnected = 1;
-        spin_unlock(&export->exp_lock);
+       spin_lock(&export->exp_lock);
+       already_disconnected = export->exp_disconnected;
+       export->exp_disconnected = 1;
+       spin_unlock(&export->exp_lock);
 
         /* class_cleanup(), abort_recovery(), and class_fail_export()
          * all end up in here, and if any of them race we shouldn't
          * call extra class_export_puts(). */
         if (already_disconnected) {
-                LASSERT(hlist_unhashed(&export->exp_nid_hash));
+                LASSERT(cfs_hlist_unhashed(&export->exp_nid_hash));
                 GOTO(no_disconn, already_disconnected);
         }
 
         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
                export->exp_handle.h_cookie);
 
-        if (!hlist_unhashed(&export->exp_nid_hash))
-                lustre_hash_del(export->exp_obd->obd_nid_hash,
-                                &export->exp_connection->c_peer.nid,
-                                &export->exp_nid_hash);
+        if (!cfs_hlist_unhashed(&export->exp_nid_hash))
+                cfs_hash_del(export->exp_obd->obd_nid_hash,
+                             &export->exp_connection->c_peer.nid,
+                             &export->exp_nid_hash);
 
         class_export_recovery_cleanup(export);
         class_unlink_export(export);
@@ -1089,8 +1211,23 @@ no_disconn:
         class_export_put(export);
         RETURN(0);
 }
+EXPORT_SYMBOL(class_disconnect);
+
+/* Return non-zero for a fully connected export */
+int class_connected_export(struct obd_export *exp)
+{
+       if (exp) {
+               int connected;
+               spin_lock(&exp->exp_lock);
+               connected = (exp->exp_conn_cnt > 0);
+               spin_unlock(&exp->exp_lock);
+               return connected;
+       }
+       return 0;
+}
+EXPORT_SYMBOL(class_connected_export);
 
-static void class_disconnect_export_list(struct list_head *list,
+static void class_disconnect_export_list(cfs_list_t *list,
                                          enum obd_option flags)
 {
         int rc;
@@ -1099,14 +1236,15 @@ static void class_disconnect_export_list(struct list_head *list,
 
         /* It's possible that an export may disconnect itself, but
          * nothing else will be added to this list. */
-        while (!list_empty(list)) {
-                exp = list_entry(list->next, struct obd_export, exp_obd_chain);
+        while (!cfs_list_empty(list)) {
+                exp = cfs_list_entry(list->next, struct obd_export,
+                                     exp_obd_chain);
                 /* need for safe call CDEBUG after obd_disconnect */
                 class_export_get(exp);
 
-                spin_lock(&exp->exp_lock);
-                exp->exp_flags = flags;
-                spin_unlock(&exp->exp_lock);
+               spin_lock(&exp->exp_lock);
+               exp->exp_flags = flags;
+               spin_unlock(&exp->exp_lock);
 
                 if (obd_uuid_equals(&exp->exp_client_uuid,
                                     &exp->exp_obd->obd_uuid)) {
@@ -1115,7 +1253,7 @@ static void class_disconnect_export_list(struct list_head *list,
                                exp);
                         /* Need to delete this now so we don't end up pointing
                          * to work_list later when this export is cleaned up. */
-                        list_del_init(&exp->exp_obd_chain);
+                        cfs_list_del_init(&exp->exp_obd_chain);
                         class_export_put(exp);
                         continue;
                 }
@@ -1137,17 +1275,17 @@ static void class_disconnect_export_list(struct list_head *list,
 
 void class_disconnect_exports(struct obd_device *obd)
 {
-        struct list_head work_list;
-        ENTRY;
+       cfs_list_t work_list;
+       ENTRY;
 
-        /* Move all of the exports from obd_exports to a work list, en masse. */
-        CFS_INIT_LIST_HEAD(&work_list);
-        spin_lock(&obd->obd_dev_lock);
-        list_splice_init(&obd->obd_exports, &work_list);
-        list_splice_init(&obd->obd_delayed_exports, &work_list);
-        spin_unlock(&obd->obd_dev_lock);
+       /* Move all of the exports from obd_exports to a work list, en masse. */
+       CFS_INIT_LIST_HEAD(&work_list);
+       spin_lock(&obd->obd_dev_lock);
+       cfs_list_splice_init(&obd->obd_exports, &work_list);
+       cfs_list_splice_init(&obd->obd_delayed_exports, &work_list);
+       spin_unlock(&obd->obd_dev_lock);
 
-        if (!list_empty(&work_list)) {
+        if (!cfs_list_empty(&work_list)) {
                 CDEBUG(D_HA, "OBD device %d (%p) has exports, "
                        "disconnecting them\n", obd->obd_minor, obd);
                 class_disconnect_export_list(&work_list,
@@ -1164,53 +1302,61 @@ EXPORT_SYMBOL(class_disconnect_exports);
 void class_disconnect_stale_exports(struct obd_device *obd,
                                     int (*test_export)(struct obd_export *))
 {
-        struct list_head work_list;
-        struct list_head *pos, *n;
-        struct obd_export *exp;
+        cfs_list_t work_list;
+       struct obd_export *exp, *n;
         int evicted = 0;
         ENTRY;
 
         CFS_INIT_LIST_HEAD(&work_list);
-        spin_lock(&obd->obd_dev_lock);
-        list_for_each_safe(pos, n, &obd->obd_exports) {
-                exp = list_entry(pos, struct obd_export, exp_obd_chain);
-                if (test_export(exp))
-                        continue;
-
+       spin_lock(&obd->obd_dev_lock);
+       cfs_list_for_each_entry_safe(exp, n, &obd->obd_exports,
+                                    exp_obd_chain) {
                 /* don't count self-export as client */
                 if (obd_uuid_equals(&exp->exp_client_uuid,
                                     &exp->exp_obd->obd_uuid))
                         continue;
 
-                list_move(&exp->exp_obd_chain, &work_list);
+               /* don't evict clients which have no slot in last_rcvd
+                * (e.g. lightweight connection) */
+               if (exp->exp_target_data.ted_lr_idx == -1)
+                       continue;
+
+               spin_lock(&exp->exp_lock);
+               if (exp->exp_failed || test_export(exp)) {
+                       spin_unlock(&exp->exp_lock);
+                       continue;
+               }
+               exp->exp_failed = 1;
+               spin_unlock(&exp->exp_lock);
+
+                cfs_list_move(&exp->exp_obd_chain, &work_list);
                 evicted++;
-                CDEBUG(D_ERROR, "%s: disconnect stale client %s@%s\n",
+                CDEBUG(D_HA, "%s: disconnect stale client %s@%s\n",
                        obd->obd_name, exp->exp_client_uuid.uuid,
                        exp->exp_connection == NULL ? "<unknown>" :
                        libcfs_nid2str(exp->exp_connection->c_peer.nid));
-                print_export_data(exp, "EVICTING");
+                print_export_data(exp, "EVICTING", 0);
         }
-        spin_unlock(&obd->obd_dev_lock);
+       spin_unlock(&obd->obd_dev_lock);
 
-        if (evicted) {
-                CDEBUG(D_HA, "%s: disconnecting %d stale clients\n",
-                       obd->obd_name, evicted);
-                obd->obd_stale_clients += evicted;
-        }
-        class_disconnect_export_list(&work_list, exp_flags_from_obd(obd) |
-                                                 OBD_OPT_ABORT_RECOV);
-        EXIT;
+       if (evicted)
+               LCONSOLE_WARN("%s: disconnecting %d stale clients\n",
+                             obd->obd_name, evicted);
+
+       class_disconnect_export_list(&work_list, exp_flags_from_obd(obd) |
+                                                OBD_OPT_ABORT_RECOV);
+       EXIT;
 }
 EXPORT_SYMBOL(class_disconnect_stale_exports);
 
 void class_fail_export(struct obd_export *exp)
 {
-        int rc, already_failed;
+       int rc, already_failed;
 
-        spin_lock(&exp->exp_lock);
-        already_failed = exp->exp_failed;
-        exp->exp_failed = 1;
-        spin_unlock(&exp->exp_lock);
+       spin_lock(&exp->exp_lock);
+       already_failed = exp->exp_failed;
+       exp->exp_failed = 1;
+       spin_unlock(&exp->exp_lock);
 
         if (already_failed) {
                 CDEBUG(D_HA, "disconnecting dead export %p/%s; skipping\n",
@@ -1224,6 +1370,9 @@ void class_fail_export(struct obd_export *exp)
         if (obd_dump_on_timeout)
                 libcfs_debug_dumplog();
 
+       /* need for safe call CDEBUG after obd_disconnect */
+       class_export_get(exp);
+
         /* Most callers into obd_disconnect are removing their own reference
          * (request, for example) in addition to the one from the hash table.
          * We don't have such a reference here, so make one. */
@@ -1234,6 +1383,7 @@ void class_fail_export(struct obd_export *exp)
         else
                 CDEBUG(D_HA, "disconnected export %p/%s\n",
                        exp, exp->exp_client_uuid.uuid);
+       class_export_put(exp);
 }
 EXPORT_SYMBOL(class_fail_export);
 
@@ -1248,13 +1398,25 @@ EXPORT_SYMBOL(obd_export_nid2str);
 
 int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
 {
-        struct obd_export *doomed_exp = NULL;
-        int exports_evicted = 0;
-
-        lnet_nid_t nid_key = libcfs_str2nid((char *)nid);
-
-        do {
-                doomed_exp = lustre_hash_lookup(obd->obd_nid_hash, &nid_key);
+       cfs_hash_t *nid_hash;
+       struct obd_export *doomed_exp = NULL;
+       int exports_evicted = 0;
+
+       lnet_nid_t nid_key = libcfs_str2nid((char *)nid);
+
+       spin_lock(&obd->obd_dev_lock);
+       /* umount has run already, so evict thread should leave
+        * its task to umount thread now */
+       if (obd->obd_stopping) {
+               spin_unlock(&obd->obd_dev_lock);
+               return exports_evicted;
+       }
+       nid_hash = obd->obd_nid_hash;
+       cfs_hash_getref(nid_hash);
+       spin_unlock(&obd->obd_dev_lock);
+
+       do {
+               doomed_exp = cfs_hash_lookup(nid_hash, &nid_key);
                 if (doomed_exp == NULL)
                         break;
 
@@ -1272,6 +1434,8 @@ int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
                 class_export_put(doomed_exp);
         } while (1);
 
+       cfs_hash_putref(nid_hash);
+
         if (!exports_evicted)
                 CDEBUG(D_HA,"%s: can't disconnect NID '%s': no exports found\n",
                        obd->obd_name, nid);
@@ -1281,17 +1445,28 @@ EXPORT_SYMBOL(obd_export_evict_by_nid);
 
 int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
 {
-        struct obd_export *doomed_exp = NULL;
-        struct obd_uuid doomed_uuid;
-        int exports_evicted = 0;
+       cfs_hash_t *uuid_hash;
+       struct obd_export *doomed_exp = NULL;
+       struct obd_uuid doomed_uuid;
+       int exports_evicted = 0;
+
+       spin_lock(&obd->obd_dev_lock);
+       if (obd->obd_stopping) {
+               spin_unlock(&obd->obd_dev_lock);
+               return exports_evicted;
+       }
+       uuid_hash = obd->obd_uuid_hash;
+       cfs_hash_getref(uuid_hash);
+       spin_unlock(&obd->obd_dev_lock);
 
         obd_str2uuid(&doomed_uuid, uuid);
         if (obd_uuid_equals(&doomed_uuid, &obd->obd_uuid)) {
                 CERROR("%s: can't evict myself\n", obd->obd_name);
+               cfs_hash_putref(uuid_hash);
                 return exports_evicted;
         }
 
-        doomed_exp = lustre_hash_lookup(obd->obd_uuid_hash, &doomed_uuid);
+       doomed_exp = cfs_hash_lookup(uuid_hash, &doomed_uuid);
 
         if (doomed_exp == NULL) {
                 CERROR("%s: can't disconnect %s: no exports found\n",
@@ -1303,126 +1478,151 @@ int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
                 class_export_put(doomed_exp);
                 exports_evicted++;
         }
+       cfs_hash_putref(uuid_hash);
 
         return exports_evicted;
 }
 EXPORT_SYMBOL(obd_export_evict_by_uuid);
 
-static void print_export_data(struct obd_export *exp, const char *status)
-{
-        struct ptlrpc_reply_state *rs;
-        struct ptlrpc_reply_state *first_reply = NULL;
-        int nreplies = 0;
+#if LUSTRE_TRACKS_LOCK_EXP_REFS
+void (*class_export_dump_hook)(struct obd_export*) = NULL;
+EXPORT_SYMBOL(class_export_dump_hook);
+#endif
 
-        spin_lock(&exp->exp_lock);
-        list_for_each_entry (rs, &exp->exp_outstanding_replies, rs_exp_list) {
-                if (nreplies == 0)
-                        first_reply = rs;
-                nreplies++;
-        }
-        spin_unlock(&exp->exp_lock);
+static void print_export_data(struct obd_export *exp, const char *status,
+                             int locks)
+{
+       struct ptlrpc_reply_state *rs;
+       struct ptlrpc_reply_state *first_reply = NULL;
+       int nreplies = 0;
+
+       spin_lock(&exp->exp_lock);
+       cfs_list_for_each_entry(rs, &exp->exp_outstanding_replies,
+                               rs_exp_list) {
+               if (nreplies == 0)
+                       first_reply = rs;
+               nreplies++;
+       }
+       spin_unlock(&exp->exp_lock);
 
         CDEBUG(D_HA, "%s: %s %p %s %s %d (%d %d %d) %d %d %d %d: %p %s "LPU64"\n",
                exp->exp_obd->obd_name, status, exp, exp->exp_client_uuid.uuid,
-               obd_export_nid2str(exp), atomic_read(&exp->exp_refcount),
-               atomic_read(&exp->exp_rpc_count),
-               atomic_read(&exp->exp_cb_count),
-               atomic_read(&exp->exp_locks_count),
+               obd_export_nid2str(exp), cfs_atomic_read(&exp->exp_refcount),
+               cfs_atomic_read(&exp->exp_rpc_count),
+               cfs_atomic_read(&exp->exp_cb_count),
+               cfs_atomic_read(&exp->exp_locks_count),
                exp->exp_disconnected, exp->exp_delayed, exp->exp_failed,
                nreplies, first_reply, nreplies > 3 ? "..." : "",
                exp->exp_last_committed);
+#if LUSTRE_TRACKS_LOCK_EXP_REFS
+        if (locks && class_export_dump_hook != NULL)
+                class_export_dump_hook(exp);
+#endif
 }
 
-void dump_exports(struct obd_device *obd)
+void dump_exports(struct obd_device *obd, int locks)
 {
         struct obd_export *exp;
 
-        spin_lock(&obd->obd_dev_lock);
-        list_for_each_entry(exp, &obd->obd_exports, exp_obd_chain)
-                print_export_data(exp, "ACTIVE");
-        list_for_each_entry(exp, &obd->obd_unlinked_exports, exp_obd_chain)
-                print_export_data(exp, "UNLINKED");
-        list_for_each_entry(exp, &obd->obd_delayed_exports, exp_obd_chain)
-                print_export_data(exp, "DELAYED");
-        spin_unlock(&obd->obd_dev_lock);
-        spin_lock(&obd_zombie_impexp_lock);
-        list_for_each_entry(exp, &obd_zombie_exports, exp_obd_chain)
-                print_export_data(exp, "ZOMBIE");
-        spin_unlock(&obd_zombie_impexp_lock);
+       spin_lock(&obd->obd_dev_lock);
+       cfs_list_for_each_entry(exp, &obd->obd_exports, exp_obd_chain)
+               print_export_data(exp, "ACTIVE", locks);
+       cfs_list_for_each_entry(exp, &obd->obd_unlinked_exports, exp_obd_chain)
+               print_export_data(exp, "UNLINKED", locks);
+       cfs_list_for_each_entry(exp, &obd->obd_delayed_exports, exp_obd_chain)
+               print_export_data(exp, "DELAYED", locks);
+       spin_unlock(&obd->obd_dev_lock);
+       spin_lock(&obd_zombie_impexp_lock);
+       cfs_list_for_each_entry(exp, &obd_zombie_exports, exp_obd_chain)
+               print_export_data(exp, "ZOMBIE", locks);
+       spin_unlock(&obd_zombie_impexp_lock);
 }
 EXPORT_SYMBOL(dump_exports);
 
 void obd_exports_barrier(struct obd_device *obd)
 {
-        int waited = 2;
-        LASSERT(list_empty(&obd->obd_exports));
-        spin_lock(&obd->obd_dev_lock);
-        while (!list_empty(&obd->obd_unlinked_exports)) {
-                spin_unlock(&obd->obd_dev_lock);
-                cfs_schedule_timeout(CFS_TASK_UNINT, cfs_time_seconds(waited));
+       int waited = 2;
+       LASSERT(cfs_list_empty(&obd->obd_exports));
+       spin_lock(&obd->obd_dev_lock);
+       while (!cfs_list_empty(&obd->obd_unlinked_exports)) {
+               spin_unlock(&obd->obd_dev_lock);
+                cfs_schedule_timeout_and_set_state(CFS_TASK_UNINT,
+                                                   cfs_time_seconds(waited));
                 if (waited > 5 && IS_PO2(waited)) {
                         LCONSOLE_WARN("%s is waiting for obd_unlinked_exports "
                                       "more than %d seconds. "
                                       "The obd refcount = %d. Is it stuck?\n",
                                       obd->obd_name, waited,
-                                      atomic_read(&obd->obd_refcount));
-                        dump_exports(obd);
+                                      cfs_atomic_read(&obd->obd_refcount));
+                        dump_exports(obd, 1);
                 }
                 waited *= 2;
-                spin_lock(&obd->obd_dev_lock);
-        }
-        spin_unlock(&obd->obd_dev_lock);
+               spin_lock(&obd->obd_dev_lock);
+       }
+       spin_unlock(&obd->obd_dev_lock);
 }
 EXPORT_SYMBOL(obd_exports_barrier);
 
+/* Total amount of zombies to be destroyed */
+static int zombies_count = 0;
+
 /**
  * kill zombie imports and exports
  */
 void obd_zombie_impexp_cull(void)
 {
-        struct obd_import *import;
-        struct obd_export *export;
-        ENTRY;
+       struct obd_import *import;
+       struct obd_export *export;
+       ENTRY;
 
-        do {
-                spin_lock(&obd_zombie_impexp_lock);
+       do {
+               spin_lock(&obd_zombie_impexp_lock);
 
                 import = NULL;
-                if (!list_empty(&obd_zombie_imports)) {
-                        import = list_entry(obd_zombie_imports.next,
-                                            struct obd_import,
-                                            imp_zombie_chain);
-                        list_del_init(&import->imp_zombie_chain);
+                if (!cfs_list_empty(&obd_zombie_imports)) {
+                        import = cfs_list_entry(obd_zombie_imports.next,
+                                                struct obd_import,
+                                                imp_zombie_chain);
+                        cfs_list_del_init(&import->imp_zombie_chain);
                 }
 
                 export = NULL;
-                if (!list_empty(&obd_zombie_exports)) {
-                        export = list_entry(obd_zombie_exports.next,
-                                            struct obd_export,
-                                            exp_obd_chain);
-                        list_del_init(&export->exp_obd_chain);
+                if (!cfs_list_empty(&obd_zombie_exports)) {
+                        export = cfs_list_entry(obd_zombie_exports.next,
+                                                struct obd_export,
+                                                exp_obd_chain);
+                        cfs_list_del_init(&export->exp_obd_chain);
                 }
 
-                spin_unlock(&obd_zombie_impexp_lock);
-
-                if (import != NULL)
-                        class_import_destroy(import);
-
-                if (export != NULL)
-                        class_export_destroy(export);
-
-        } while (import != NULL || export != NULL);
-        EXIT;
+               spin_unlock(&obd_zombie_impexp_lock);
+
+               if (import != NULL) {
+                       class_import_destroy(import);
+                       spin_lock(&obd_zombie_impexp_lock);
+                       zombies_count--;
+                       spin_unlock(&obd_zombie_impexp_lock);
+               }
+
+               if (export != NULL) {
+                       class_export_destroy(export);
+                       spin_lock(&obd_zombie_impexp_lock);
+                       zombies_count--;
+                       spin_unlock(&obd_zombie_impexp_lock);
+               }
+
+               cfs_cond_resched();
+       } while (import != NULL || export != NULL);
+       EXIT;
 }
 
-static struct completion        obd_zombie_start;
-static struct completion        obd_zombie_stop;
-static unsigned long            obd_zombie_flags;
-static cfs_waitq_t              obd_zombie_waitq;
-static pid_t                    obd_zombie_pid;
+static struct completion       obd_zombie_start;
+static struct completion       obd_zombie_stop;
+static unsigned long           obd_zombie_flags;
+static cfs_waitq_t             obd_zombie_waitq;
+static pid_t                   obd_zombie_pid;
 
 enum {
-        OBD_ZOMBIE_STOP   = 1 << 1
+       OBD_ZOMBIE_STOP         = 0x0001,
 };
 
 /**
@@ -1430,46 +1630,45 @@ enum {
  */
 static int obd_zombie_impexp_check(void *arg)
 {
-        int rc;
+       int rc;
 
-        spin_lock(&obd_zombie_impexp_lock);
-        rc = list_empty(&obd_zombie_imports) &&
-             list_empty(&obd_zombie_exports) &&
-             !test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+       spin_lock(&obd_zombie_impexp_lock);
+       rc = (zombies_count == 0) &&
+            !test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+       spin_unlock(&obd_zombie_impexp_lock);
 
-        spin_unlock(&obd_zombie_impexp_lock);
-
-        RETURN(rc);
+       RETURN(rc);
 }
 
 /**
  * Add export to the obd_zombe thread and notify it.
  */
 static void obd_zombie_export_add(struct obd_export *exp) {
-        spin_lock(&exp->exp_obd->obd_dev_lock);
-        LASSERT(!list_empty(&exp->exp_obd_chain));
-        list_del_init(&exp->exp_obd_chain);
-        spin_unlock(&exp->exp_obd->obd_dev_lock);
-        spin_lock(&obd_zombie_impexp_lock);
-        list_add(&exp->exp_obd_chain, &obd_zombie_exports);
-        spin_unlock(&obd_zombie_impexp_lock);
-
-        if (obd_zombie_impexp_notify != NULL)
-                obd_zombie_impexp_notify();
+       spin_lock(&exp->exp_obd->obd_dev_lock);
+       LASSERT(!cfs_list_empty(&exp->exp_obd_chain));
+       cfs_list_del_init(&exp->exp_obd_chain);
+       spin_unlock(&exp->exp_obd->obd_dev_lock);
+       spin_lock(&obd_zombie_impexp_lock);
+       zombies_count++;
+       cfs_list_add(&exp->exp_obd_chain, &obd_zombie_exports);
+       spin_unlock(&obd_zombie_impexp_lock);
+
+       obd_zombie_impexp_notify();
 }
 
 /**
  * Add import to the obd_zombe thread and notify it.
  */
 static void obd_zombie_import_add(struct obd_import *imp) {
-        LASSERT(imp->imp_sec == NULL);
-        spin_lock(&obd_zombie_impexp_lock);
-        LASSERT(list_empty(&imp->imp_zombie_chain));
-        list_add(&imp->imp_zombie_chain, &obd_zombie_imports);
-        spin_unlock(&obd_zombie_impexp_lock);
-
-        if (obd_zombie_impexp_notify != NULL)
-                obd_zombie_impexp_notify();
+       LASSERT(imp->imp_sec == NULL);
+       LASSERT(imp->imp_rq_pool == NULL);
+       spin_lock(&obd_zombie_impexp_lock);
+       LASSERT(cfs_list_empty(&imp->imp_zombie_chain));
+       zombies_count++;
+       cfs_list_add(&imp->imp_zombie_chain, &obd_zombie_imports);
+       spin_unlock(&obd_zombie_impexp_lock);
+
+       obd_zombie_impexp_notify();
 }
 
 /**
@@ -1477,7 +1676,12 @@ static void obd_zombie_import_add(struct obd_import *imp) {
  */
 static void obd_zombie_impexp_notify(void)
 {
-        cfs_waitq_signal(&obd_zombie_waitq);
+        /*
+         * Make sure obd_zomebie_impexp_thread get this notification.
+         * It is possible this signal only get by obd_zombie_barrier, and
+         * barrier gulps this notification and sleeps away and hangs ensues
+         */
+        cfs_waitq_broadcast(&obd_zombie_waitq);
 }
 
 /**
@@ -1485,14 +1689,13 @@ static void obd_zombie_impexp_notify(void)
  */
 static int obd_zombie_is_idle(void)
 {
-        int rc;
+       int rc;
 
-        LASSERT(!test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags));
-        spin_lock(&obd_zombie_impexp_lock);
-        rc = list_empty(&obd_zombie_imports) &&
-             list_empty(&obd_zombie_exports);
-        spin_unlock(&obd_zombie_impexp_lock);
-        return rc;
+       LASSERT(!test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags));
+       spin_lock(&obd_zombie_impexp_lock);
+       rc = (zombies_count == 0);
+       spin_unlock(&obd_zombie_impexp_lock);
+       return rc;
 }
 
 /**
@@ -1516,18 +1719,19 @@ EXPORT_SYMBOL(obd_zombie_barrier);
  */
 static int obd_zombie_impexp_thread(void *unused)
 {
-        int rc;
+       int rc;
 
-        if ((rc = cfs_daemonize_ctxt("obd_zombid"))) {
-                complete(&obd_zombie_start);
-                RETURN(rc);
-        }
+       rc = cfs_daemonize_ctxt("obd_zombid");
+       if (rc != 0) {
+               complete(&obd_zombie_start);
+               RETURN(rc);
+       }
 
-        complete(&obd_zombie_start);
+       complete(&obd_zombie_start);
 
-        obd_zombie_pid = cfs_curproc_pid();
+       obd_zombie_pid = cfs_curproc_pid();
 
-        while(!test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags)) {
+       while (!test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags)) {
                 struct l_wait_info lwi = { 0 };
 
                 l_wait_event(obd_zombie_waitq,
@@ -1541,14 +1745,14 @@ static int obd_zombie_impexp_thread(void *unused)
                 cfs_waitq_signal(&obd_zombie_waitq);
         }
 
-        complete(&obd_zombie_stop);
+       complete(&obd_zombie_stop);
 
-        RETURN(0);
+       RETURN(0);
 }
 
 #else /* ! KERNEL */
 
-static atomic_t zombie_recur = ATOMIC_INIT(0);
+static cfs_atomic_t zombie_recur = CFS_ATOMIC_INIT(0);
 static void *obd_zombie_impexp_work_cb;
 static void *obd_zombie_impexp_idle_cb;
 
@@ -1556,11 +1760,11 @@ int obd_zombie_impexp_kill(void *arg)
 {
         int rc = 0;
 
-        if (atomic_inc_return(&zombie_recur) == 1) {
+        if (cfs_atomic_inc_return(&zombie_recur) == 1) {
                 obd_zombie_impexp_cull();
                 rc = 1;
         }
-        atomic_dec(&zombie_recur);
+        cfs_atomic_dec(&zombie_recur);
         return rc;
 }
 
@@ -1571,22 +1775,22 @@ int obd_zombie_impexp_kill(void *arg)
  */
 int obd_zombie_impexp_init(void)
 {
-        int rc;
+       int rc;
 
-        CFS_INIT_LIST_HEAD(&obd_zombie_imports);
-        CFS_INIT_LIST_HEAD(&obd_zombie_exports);
-        spin_lock_init(&obd_zombie_impexp_lock);
-        init_completion(&obd_zombie_start);
-        init_completion(&obd_zombie_stop);
-        cfs_waitq_init(&obd_zombie_waitq);
-        obd_zombie_pid = 0;
+       CFS_INIT_LIST_HEAD(&obd_zombie_imports);
+       CFS_INIT_LIST_HEAD(&obd_zombie_exports);
+       spin_lock_init(&obd_zombie_impexp_lock);
+       init_completion(&obd_zombie_start);
+       init_completion(&obd_zombie_stop);
+       cfs_waitq_init(&obd_zombie_waitq);
+       obd_zombie_pid = 0;
 
 #ifdef __KERNEL__
-        rc = cfs_kernel_thread(obd_zombie_impexp_thread, NULL, 0);
-        if (rc < 0)
-                RETURN(rc);
+       rc = cfs_create_thread(obd_zombie_impexp_thread, NULL, 0);
+       if (rc < 0)
+               RETURN(rc);
 
-        wait_for_completion(&obd_zombie_start);
+       wait_for_completion(&obd_zombie_start);
 #else
 
         obd_zombie_impexp_work_cb =
@@ -1605,13 +1809,80 @@ int obd_zombie_impexp_init(void)
  */
 void obd_zombie_impexp_stop(void)
 {
-        set_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+       set_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
         obd_zombie_impexp_notify();
 #ifdef __KERNEL__
-        wait_for_completion(&obd_zombie_stop);
+       wait_for_completion(&obd_zombie_stop);
 #else
         liblustre_deregister_wait_callback(obd_zombie_impexp_work_cb);
         liblustre_deregister_idle_callback(obd_zombie_impexp_idle_cb);
 #endif
 }
 
+/***** Kernel-userspace comm helpers *******/
+
+/* Get length of entire message, including header */
+int kuc_len(int payload_len)
+{
+        return sizeof(struct kuc_hdr) + payload_len;
+}
+EXPORT_SYMBOL(kuc_len);
+
+/* Get a pointer to kuc header, given a ptr to the payload
+ * @param p Pointer to payload area
+ * @returns Pointer to kuc header
+ */
+struct kuc_hdr * kuc_ptr(void *p)
+{
+        struct kuc_hdr *lh = ((struct kuc_hdr *)p) - 1;
+        LASSERT(lh->kuc_magic == KUC_MAGIC);
+        return lh;
+}
+EXPORT_SYMBOL(kuc_ptr);
+
+/* Test if payload is part of kuc message
+ * @param p Pointer to payload area
+ * @returns boolean
+ */
+int kuc_ispayload(void *p)
+{
+        struct kuc_hdr *kh = ((struct kuc_hdr *)p) - 1;
+
+        if (kh->kuc_magic == KUC_MAGIC)
+                return 1;
+        else
+                return 0;
+}
+EXPORT_SYMBOL(kuc_ispayload);
+
+/* Alloc space for a message, and fill in header
+ * @return Pointer to payload area
+ */
+void *kuc_alloc(int payload_len, int transport, int type)
+{
+        struct kuc_hdr *lh;
+        int len = kuc_len(payload_len);
+
+        OBD_ALLOC(lh, len);
+        if (lh == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        lh->kuc_magic = KUC_MAGIC;
+        lh->kuc_transport = transport;
+        lh->kuc_msgtype = type;
+        lh->kuc_msglen = len;
+
+        return (void *)(lh + 1);
+}
+EXPORT_SYMBOL(kuc_alloc);
+
+/* Takes pointer to payload area */
+inline void kuc_free(void *p, int payload_len)
+{
+        struct kuc_hdr *lh = kuc_ptr(p);
+        OBD_FREE(lh, kuc_len(payload_len));
+}
+EXPORT_SYMBOL(kuc_free);
+
+
+