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Merge "Remove EXPORT_SYMBOL for static function."
[fs/lustre-release.git] / lustre / obdclass / genops.c
index 25d12e4..9a9adfa 100644 (file)
@@ -1,25 +1,39 @@
 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
  * vim:expandtab:shiftwidth=8:tabstop=8:
  *
- *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
+ * GPL HEADER START
  *
- *   This file is part of the Lustre file system, http://www.lustre.org
- *   Lustre is a trademark of Cluster File Systems, Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
- *   You may have signed or agreed to another license before downloading
- *   this software.  If so, you are bound by the terms and conditions
- *   of that agreement, and the following does not apply to you.  See the
- *   LICENSE file included with this distribution for more information.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
  *
- *   If you did not agree to a different license, then this copy of Lustre
- *   is open source software; you can redistribute it and/or modify it
- *   under the terms of version 2 of the GNU General Public License as
- *   published by the Free Software Foundation.
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
  *
- *   In either case, Lustre is distributed in the hope that it will be
- *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
- *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   license text for more details.
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/obdclass/genops.c
  *
  * These are the only exported functions, they provide some generic
  * infrastructure for managing object devices
 #include <obd_ost.h>
 #include <obd_class.h>
 #include <lprocfs_status.h>
-#include <class_hash.h>
 
-extern struct list_head obd_types;
-spinlock_t obd_types_lock;
+extern cfs_list_t obd_types;
+cfs_spinlock_t obd_types_lock;
 
 cfs_mem_cache_t *obd_device_cachep;
 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;
-void            (*obd_zombie_impexp_notify)(void) = NULL;
-EXPORT_SYMBOL(obd_zombie_impexp_notify);
-
+cfs_list_t      obd_zombie_imports;
+cfs_list_t      obd_zombie_exports;
+cfs_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, int locks);
 
 int (*ptlrpc_put_connection_superhack)(struct ptlrpc_connection *c);
 
@@ -59,37 +74,41 @@ static struct obd_device *obd_device_alloc(void)
 {
         struct obd_device *obd;
 
-        OBD_SLAB_ALLOC_PTR(obd, obd_device_cachep);
+        OBD_SLAB_ALLOC_PTR_GFP(obd, obd_device_cachep, CFS_ALLOC_IO);
         if (obd != NULL) {
                 obd->obd_magic = OBD_DEVICE_MAGIC;
         }
         return obd;
 }
-EXPORT_SYMBOL(obd_device_alloc);
 
 static void obd_device_free(struct obd_device *obd)
 {
         LASSERT(obd != NULL);
-        LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "obd %p obd_magic %08x != %08x\n", 
+        LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "obd %p obd_magic %08x != %08x\n",
                  obd, obd->obd_magic, OBD_DEVICE_MAGIC);
+        if (obd->obd_namespace != NULL) {
+                CERROR("obd %p: namespace %p was not properly cleaned up (obd_force=%d)!\n",
+                       obd, obd->obd_namespace, obd->obd_force);
+                LBUG();
+        }
+        lu_ref_fini(&obd->obd_reference);
         OBD_SLAB_FREE_PTR(obd, obd_device_cachep);
 }
-EXPORT_SYMBOL(obd_device_free);
 
 struct obd_type *class_search_type(const char *name)
 {
-        struct list_head *tmp;
+        cfs_list_t *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);
+        cfs_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);
+                        cfs_spin_unlock(&obd_types_lock);
                         return type;
                 }
         }
-        spin_unlock(&obd_types_lock);
+        cfs_spin_unlock(&obd_types_lock);
         return NULL;
 }
 
@@ -97,10 +116,10 @@ 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(modname)) {
+                if (!cfs_request_module("%s", modname)) {
                         CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
                         type = class_search_type(name);
                 } else {
@@ -110,10 +129,10 @@ struct obd_type *class_get_type(const char *name)
         }
 #endif
         if (type) {
-                spin_lock(&type->obd_type_lock);
+                cfs_spin_lock(&type->obd_type_lock);
                 type->typ_refcnt++;
-                try_module_get(type->typ_dt_ops->o_owner);
-                spin_unlock(&type->obd_type_lock);
+                cfs_try_module_get(type->typ_dt_ops->o_owner);
+                cfs_spin_unlock(&type->obd_type_lock);
         }
         return type;
 }
@@ -121,16 +140,16 @@ struct obd_type *class_get_type(const char *name)
 void class_put_type(struct obd_type *type)
 {
         LASSERT(type);
-        spin_lock(&type->obd_type_lock);
+        cfs_spin_lock(&type->obd_type_lock);
         type->typ_refcnt--;
-        module_put(type->typ_dt_ops->o_owner);
-        spin_unlock(&type->obd_type_lock);
+        cfs_module_put(type->typ_dt_ops->o_owner);
+        cfs_spin_unlock(&type->obd_type_lock);
 }
 
 #define CLASS_MAX_NAME 1024
 
-int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops, 
-                        struct lprocfs_vars *vars, const char *name, 
+int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
+                        struct lprocfs_vars *vars, const char *name,
                         struct lu_device_type *ldt)
 {
         struct obd_type *type;
@@ -153,9 +172,9 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
         OBD_ALLOC_PTR(type->typ_dt_ops);
         OBD_ALLOC_PTR(type->typ_md_ops);
         OBD_ALLOC(type->typ_name, strlen(name) + 1);
-        
-        if (type->typ_dt_ops == NULL || 
-            type->typ_md_ops == NULL || 
+
+        if (type->typ_dt_ops == NULL ||
+            type->typ_md_ops == NULL ||
             type->typ_name == NULL)
                 GOTO (failed, rc);
 
@@ -164,7 +183,7 @@ 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);
+        cfs_spin_lock_init(&type->obd_type_lock);
 
 #ifdef LPROCFS
         type->typ_procroot = lprocfs_register(type->typ_name, proc_lustre_root,
@@ -177,14 +196,14 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
 #endif
         if (ldt != NULL) {
                 type->typ_lu = ldt;
-                rc = ldt->ldt_ops->ldto_init(ldt);
+                rc = lu_device_type_init(ldt);
                 if (rc != 0)
                         GOTO (failed, rc);
         }
 
-        spin_lock(&obd_types_lock);
-        list_add(&type->typ_chain, &obd_types);
-        spin_unlock(&obd_types_lock);
+        cfs_spin_lock(&obd_types_lock);
+        cfs_list_add(&type->typ_chain, &obd_types);
+        cfs_spin_unlock(&obd_types_lock);
 
         RETURN (0);
 
@@ -223,11 +242,11 @@ int class_unregister_type(const char *name)
         }
 
         if (type->typ_lu)
-                type->typ_lu->ldt_ops->ldto_fini(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);
+        cfs_spin_lock(&obd_types_lock);
+        cfs_list_del(&type->typ_chain);
+        cfs_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);
@@ -237,6 +256,17 @@ int class_unregister_type(const char *name)
         RETURN(0);
 } /* class_unregister_type */
 
+/**
+ * Create a new obd device.
+ *
+ * Find an empty slot in ::obd_devs[], create a new obd device in it.
+ *
+ * \param[in] type_name obd device type string.
+ * \param[in] name      obd device name.
+ *
+ * \retval NULL if create fails, otherwise return the obd device
+ *         pointer created.
+ */
 struct obd_device *class_newdev(const char *type_name, const char *name)
 {
         struct obd_device *result = NULL;
@@ -245,25 +275,25 @@ struct obd_device *class_newdev(const char *type_name, const char *name)
         int i;
         int new_obd_minor = 0;
 
-        if (strlen(name) > MAX_OBD_NAME) {
+        if (strlen(name) >= MAX_OBD_NAME) {
                 CERROR("name/uuid must be < %u bytes long\n", MAX_OBD_NAME);
                 RETURN(ERR_PTR(-EINVAL));
         }
 
-        type = class_get_type(type_name); 
+        type = class_get_type(type_name);
         if (type == NULL){
                 CERROR("OBD: unknown type: %s\n", type_name);
                 RETURN(ERR_PTR(-ENODEV));
         }
 
         newdev = obd_device_alloc();
-        if (newdev == NULL) { 
+        if (newdev == NULL) {
                 class_put_type(type);
                 RETURN(ERR_PTR(-ENOMEM));
         }
         LASSERT(newdev->obd_magic == OBD_DEVICE_MAGIC);
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
                 if (obd && obd->obd_name &&
@@ -288,18 +318,19 @@ struct obd_device *class_newdev(const char *type_name, const char *name)
                         result->obd_minor = i;
                         new_obd_minor = i;
                         result->obd_type = type;
-                        memcpy(result->obd_name, name, strlen(name));
+                        strncpy(result->obd_name, name,
+                                sizeof(result->obd_name) - 1);
                         obd_devs[i] = result;
                 }
         }
-        spin_unlock(&obd_dev_lock);
-        
+        cfs_spin_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);
         }
-        
+
         if (IS_ERR(result)) {
                 obd_device_free(newdev);
                 class_put_type(type);
@@ -323,9 +354,9 @@ void class_release_dev(struct obd_device *obd)
         CDEBUG(D_INFO, "Release obd device %s obd_type name =%s\n",
                obd->obd_name,obd->obd_type->typ_name);
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_lock(&obd_dev_lock);
         obd_devs[obd->obd_minor] = NULL;
-        spin_unlock(&obd_dev_lock);
+        cfs_spin_unlock(&obd_dev_lock);
         obd_device_free(obd);
 
         class_put_type(obd_type);
@@ -338,7 +369,7 @@ int class_name2dev(const char *name)
         if (!name)
                 return -1;
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_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) {
@@ -346,13 +377,13 @@ int class_name2dev(const char *name)
                            out any references */
                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
                         if (obd->obd_attached) {
-                                spin_unlock(&obd_dev_lock);
+                                cfs_spin_unlock(&obd_dev_lock);
                                 return i;
                         }
                         break;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+        cfs_spin_unlock(&obd_dev_lock);
 
         return -1;
 }
@@ -370,16 +401,16 @@ int class_uuid2dev(struct obd_uuid *uuid)
 {
         int i;
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_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);
+                        cfs_spin_unlock(&obd_dev_lock);
                         return i;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+        cfs_spin_unlock(&obd_dev_lock);
 
         return -1;
 }
@@ -392,15 +423,22 @@ struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
         return class_num2obd(dev);
 }
 
+/**
+ * Get obd device from ::obd_devs[]
+ *
+ * \param num [in] array index
+ *
+ * \retval NULL if ::obd_devs[\a num] does not contains an obd device
+ *         otherwise return the obd device there.
+ */
 struct obd_device *class_num2obd(int num)
 {
         struct obd_device *obd = NULL;
 
         if (num < class_devno_max()) {
                 obd = obd_devs[num];
-                if (obd == NULL) {
+                if (obd == NULL)
                         return NULL;
-                }
 
                 LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC,
                          "%p obd_magic %08x != %08x\n",
@@ -418,7 +456,7 @@ void class_obd_list(void)
         char *status;
         int i;
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
                 if (obd == NULL)
@@ -434,9 +472,9 @@ 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);
+        cfs_spin_unlock(&obd_dev_lock);
         return;
 }
 
@@ -449,7 +487,7 @@ struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 {
         int i;
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_lock(&obd_dev_lock);
         for (i = 0; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
                 if (obd == NULL)
@@ -460,28 +498,16 @@ 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);
+                                cfs_spin_unlock(&obd_dev_lock);
                                 return obd;
                         }
                 }
         }
-        spin_unlock(&obd_dev_lock);
+        cfs_spin_unlock(&obd_dev_lock);
 
         return NULL;
 }
 
-struct obd_device *class_find_client_notype(struct obd_uuid *tgt_uuid,
-                                            struct obd_uuid *grp_uuid)
-{
-        struct obd_device *obd;
-
-        obd = class_find_client_obd(tgt_uuid, LUSTRE_MDC_NAME, NULL);
-        if (!obd)
-                obd = class_find_client_obd(tgt_uuid, LUSTRE_OSC_NAME,
-                                            grp_uuid);
-        return 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
    at is saved in *next. If next is NULL, then the first matching device
@@ -497,7 +523,7 @@ struct obd_device * class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
         else
                 return NULL;
 
-        spin_lock(&obd_dev_lock);
+        cfs_spin_lock(&obd_dev_lock);
         for (; i < class_devno_max(); i++) {
                 struct obd_device *obd = class_num2obd(i);
                 if (obd == NULL)
@@ -505,15 +531,58 @@ struct obd_device * class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
                         if (next != NULL)
                                 *next = i+1;
-                        spin_unlock(&obd_dev_lock);
+                        cfs_spin_unlock(&obd_dev_lock);
                         return obd;
                 }
         }
-        spin_unlock(&obd_dev_lock);
+        cfs_spin_unlock(&obd_dev_lock);
 
         return NULL;
 }
 
+/**
+ * to notify sptlrpc log for \a fsname has changed, let every relevant OBD
+ * adjust sptlrpc settings accordingly.
+ */
+int class_notify_sptlrpc_conf(const char *fsname, int namelen)
+{
+        struct obd_device  *obd;
+        const char         *type;
+        int                 i, rc = 0, rc2;
+
+        LASSERT(namelen > 0);
+
+        cfs_spin_lock(&obd_dev_lock);
+        for (i = 0; i < class_devno_max(); i++) {
+                obd = class_num2obd(i);
+
+                if (obd == NULL || obd->obd_set_up == 0 || obd->obd_stopping)
+                        continue;
+
+                /* only notify mdc, osc, mdt, ost */
+                type = obd->obd_type->typ_name;
+                if (strcmp(type, LUSTRE_MDC_NAME) != 0 &&
+                    strcmp(type, LUSTRE_OSC_NAME) != 0 &&
+                    strcmp(type, LUSTRE_MDT_NAME) != 0 &&
+                    strcmp(type, LUSTRE_OST_NAME) != 0)
+                        continue;
+
+                if (strncmp(obd->obd_name, fsname, namelen))
+                        continue;
+
+                class_incref(obd, __FUNCTION__, obd);
+                cfs_spin_unlock(&obd_dev_lock);
+                rc2 = obd_set_info_async(obd->obd_self_export,
+                                         sizeof(KEY_SPTLRPC_CONF),
+                                         KEY_SPTLRPC_CONF, 0, NULL, NULL);
+                rc = rc ? rc : rc2;
+                class_decref(obd, __FUNCTION__, obd);
+                cfs_spin_lock(&obd_dev_lock);
+        }
+        cfs_spin_unlock(&obd_dev_lock);
+        return rc;
+}
+EXPORT_SYMBOL(class_notify_sptlrpc_conf);
 
 void obd_cleanup_caches(void)
 {
@@ -549,7 +618,7 @@ int obd_init_caches(void)
 
         LASSERT(obd_device_cachep == NULL);
         obd_device_cachep = cfs_mem_cache_create("ll_obd_dev_cache",
-                                                 sizeof(struct obd_device), 
+                                                 sizeof(struct obd_device),
                                                  0, 0);
         if (!obd_device_cachep)
                 GOTO(out, -ENOMEM);
@@ -637,35 +706,12 @@ struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 }
 
 /* Export management functions */
-static void export_handle_addref(void *export)
-{
-        class_export_get(export);
-}
-
-void __class_export_put(struct obd_export *exp)
-{
-        if (atomic_dec_and_test(&exp->exp_refcount)) {
-                LASSERT (list_empty(&exp->exp_obd_chain));
-
-                CDEBUG(D_IOCTL, "final put %p/%s\n",
-                       exp, exp->exp_client_uuid.uuid);
-        
-                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();
-        }
-}
-EXPORT_SYMBOL(__class_export_put);
-
-void class_export_destroy(struct obd_export *exp)
+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);
 
         CDEBUG(D_IOCTL, "destroying export %p/%s for %s\n", exp,
                exp->exp_client_uuid.uuid, obd->obd_name);
@@ -676,14 +722,51 @@ void class_export_destroy(struct obd_export *exp)
         if (exp->exp_connection)
                 ptlrpc_put_connection_superhack(exp->exp_connection);
 
-        LASSERT(list_empty(&exp->exp_outstanding_replies));
+        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_queued_rpc));
         obd_destroy_export(exp);
+        class_decref(obd, "export", exp);
+
         OBD_FREE_RCU(exp, sizeof(*exp), &exp->exp_handle);
-        class_decref(obd);
         EXIT;
 }
 
+static void export_handle_addref(void *export)
+{
+        class_export_get(export);
+}
+
+struct obd_export *class_export_get(struct obd_export *exp)
+{
+        cfs_atomic_inc(&exp->exp_refcount);
+        CDEBUG(D_INFO, "GETting export %p : new refcount %d\n", exp,
+               cfs_atomic_read(&exp->exp_refcount));
+        return exp;
+}
+EXPORT_SYMBOL(class_export_get);
+
+void class_export_put(struct obd_export *exp)
+{
+        LASSERT(exp != NULL);
+        LASSERT_ATOMIC_GT_LT(&exp->exp_refcount, 0, 0x5a5a5a);
+        CDEBUG(D_INFO, "PUTting export %p : new refcount %d\n", exp,
+               cfs_atomic_read(&exp->exp_refcount) - 1);
+
+        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);
+        }
+}
+EXPORT_SYMBOL(class_export_put);
+
 /* Creates a new export, adds it to the hash table, and returns a
  * pointer to it. The refcount is 2: one for the hash reference, and
  * one for the pointer returned by this function. */
@@ -691,56 +774,88 @@ 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;
 
         OBD_ALLOC_PTR(export);
         if (!export)
                 return ERR_PTR(-ENOMEM);
 
         export->exp_conn_cnt = 0;
-        atomic_set(&export->exp_refcount, 2);
-        atomic_set(&export->exp_rpc_count, 0);
+        export->exp_lock_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);
+        cfs_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);
-        /* XXX this should be in LDLM init */
-        CFS_INIT_LIST_HEAD(&export->exp_ldlm_data.led_held_locks);
-        spin_lock_init(&export->exp_ldlm_data.led_lock);
-
+        cfs_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 = CURRENT_SECONDS;
-        spin_lock_init(&export->exp_lock);
-        INIT_HLIST_NODE(&export->exp_uuid_hash);
-        INIT_HLIST_NODE(&export->exp_nid_hash);
+        export->exp_last_request_time = cfs_time_current_sec();
+        cfs_spin_lock_init(&export->exp_lock);
+        cfs_spin_lock_init(&export->exp_rpc_lock);
+        CFS_INIT_HLIST_NODE(&export->exp_uuid_hash);
+        CFS_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);
+        cfs_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);
+        cfs_spin_unlock(&obd->obd_dev_lock);
+
         if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
-               rc = lustre_hash_additem_unique(obd->obd_uuid_hash_body, cluuid, 
-                                               &export->exp_uuid_hash);
-               if (rc != 0) {
-                       CWARN("%s: denying duplicate export for %s\n",
-                             obd->obd_name, cluuid->uuid);
-                       spin_unlock(&obd->obd_dev_lock);
-                       class_handle_unhash(&export->exp_handle);
-                       OBD_FREE_PTR(export);
-                       return ERR_PTR(-EALREADY);
-               }
+                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);
+                        GOTO(exit_err, rc = -EALREADY);
+                }
         }
 
-        LASSERT(!obd->obd_stopping); /* shouldn't happen, but might race */
-        class_incref(obd);
-        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_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);
+        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);
+        cfs_spin_unlock(&obd->obd_dev_lock);
+        cfs_hash_putref(hash);
+        RETURN(export);
 
-        return export;
+exit_unlock:
+        cfs_spin_unlock(&obd->obd_dev_lock);
+exit_err:
+        if (hash)
+                cfs_hash_putref(hash);
+        class_handle_unhash(&export->exp_handle);
+        LASSERT(cfs_hlist_unhashed(&export->exp_uuid_hash));
+        obd_destroy_export(export);
+        OBD_FREE_PTR(export);
+        return ERR_PTR(rc);
 }
 EXPORT_SYMBOL(class_new_export);
 
@@ -748,22 +863,49 @@ void class_unlink_export(struct obd_export *exp)
 {
         class_handle_unhash(&exp->exp_handle);
 
-        spin_lock(&exp->exp_obd->obd_dev_lock);
+        cfs_spin_lock(&exp->exp_obd->obd_dev_lock);
         /* delete an uuid-export hashitem from hashtables */
-        if (!hlist_unhashed(&exp->exp_uuid_hash)) {
-                lustre_hash_delitem(exp->exp_obd->obd_uuid_hash_body, 
-                                    &exp->exp_client_uuid, &exp->exp_uuid_hash);
-        }
-        list_del_init(&exp->exp_obd_chain);
-        list_del_init(&exp->exp_obd_chain_timed);
-        exp->exp_obd->obd_num_exports--;
-        spin_unlock(&exp->exp_obd->obd_dev_lock);
+        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--;
+        cfs_spin_unlock(&exp->exp_obd->obd_dev_lock);
         class_export_put(exp);
 }
 EXPORT_SYMBOL(class_unlink_export);
 
 /* Import management functions */
+void class_import_destroy(struct obd_import *imp)
+{
+        ENTRY;
+
+        CDEBUG(D_IOCTL, "destroying import %p for %s\n", imp,
+                imp->imp_obd->obd_name);
+
+        LASSERT_ATOMIC_ZERO(&imp->imp_refcount);
+
+        ptlrpc_put_connection_superhack(imp->imp_connection);
+
+        while (!cfs_list_empty(&imp->imp_conn_list)) {
+                struct obd_import_conn *imp_conn;
+
+                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));
+        }
+
+        LASSERT(imp->imp_sec == NULL);
+        class_decref(imp->imp_obd, "import", imp);
+        OBD_FREE_RCU(imp, sizeof(*imp), &imp->imp_handle);
+        EXIT;
+}
+
 static void import_handle_addref(void *import)
 {
         class_import_get(import);
@@ -771,68 +913,45 @@ static void import_handle_addref(void *import)
 
 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);
-        CDEBUG(D_INFO, "import %p refcount=%d\n", import,
-               atomic_read(&import->imp_refcount));
+        cfs_atomic_inc(&import->imp_refcount);
+        CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", import,
+               cfs_atomic_read(&import->imp_refcount),
+               import->imp_obd->obd_name);
         return import;
 }
 EXPORT_SYMBOL(class_import_get);
 
-void class_import_put(struct obd_import *import)
+void class_import_put(struct obd_import *imp)
 {
         ENTRY;
 
-        CDEBUG(D_INFO, "import %p refcount=%d\n", import,
-               atomic_read(&import->imp_refcount) - 1);
+        LASSERT(cfs_list_empty(&imp->imp_zombie_chain));
+        LASSERT_ATOMIC_GE_LT(&imp->imp_refcount, 0, 0x5a5a5a);
 
-        LASSERT(atomic_read(&import->imp_refcount) > 0);
-        LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
-        LASSERT(list_empty(&import->imp_zombie_chain));
+        CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", imp,
+               cfs_atomic_read(&imp->imp_refcount) - 1,
+               imp->imp_obd->obd_name);
 
-        if (atomic_dec_and_test(&import->imp_refcount)) {
-
-                CDEBUG(D_INFO, "final put import %p\n", import);
-                
-                spin_lock(&obd_zombie_impexp_lock);
-                list_add(&import->imp_zombie_chain, &obd_zombie_imports);
-                spin_unlock(&obd_zombie_impexp_lock);
-
-                if (obd_zombie_impexp_notify != NULL)
-                        obd_zombie_impexp_notify();
+        if (cfs_atomic_dec_and_test(&imp->imp_refcount)) {
+                CDEBUG(D_INFO, "final put import %p\n", imp);
+                obd_zombie_import_add(imp);
         }
 
         EXIT;
 }
+EXPORT_SYMBOL(class_import_put);
 
-void class_import_destroy(struct obd_import *import)
-{
-        ENTRY;
-        
-        CDEBUG(D_IOCTL, "destroying import %p for %s\n", import,
-                import->imp_obd->obd_name);
-
-        LASSERT(atomic_read(&import->imp_refcount) == 0);
-
-        ptlrpc_put_connection_superhack(import->imp_connection);
-
-        while (!list_empty(&import->imp_conn_list)) {
-                struct obd_import_conn *imp_conn;
-
-                imp_conn = list_entry(import->imp_conn_list.next,
-                                      struct obd_import_conn, oic_item);
-                list_del(&imp_conn->oic_item);
-                ptlrpc_put_connection_superhack(imp_conn->oic_conn);
-                OBD_FREE(imp_conn, sizeof(*imp_conn));
+static void init_imp_at(struct imp_at *at) {
+        int i;
+        at_init(&at->iat_net_latency, 0, 0);
+        for (i = 0; i < IMP_AT_MAX_PORTALS; i++) {
+                /* max service estimates are tracked on the server side, so
+                   don't use the AT history here, just use the last reported
+                   val. (But keep hist for proc histogram, worst_ever) */
+                at_init(&at->iat_service_estimate[i], INITIAL_CONNECT_TIMEOUT,
+                        AT_FLG_NOHIST);
         }
-
-        LASSERT(import->imp_sec == NULL);
-        class_decref(import->imp_obd);
-        OBD_FREE_RCU(import, sizeof(*import), &import->imp_handle);
-        EXIT;
 }
-EXPORT_SYMBOL(class_import_put);
 
 struct obd_import *class_new_import(struct obd_device *obd)
 {
@@ -846,24 +965,26 @@ 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);
+        cfs_spin_lock_init(&imp->imp_lock);
         imp->imp_last_success_conn = 0;
         imp->imp_state = LUSTRE_IMP_NEW;
-        imp->imp_obd = class_incref(obd);
-        sema_init(&imp->imp_sec_mutex, 1);
+        imp->imp_obd = class_incref(obd, "import", imp);
+        cfs_sema_init(&imp->imp_sec_mutex, 1);
         cfs_waitq_init(&imp->imp_recovery_waitq);
 
-        atomic_set(&imp->imp_refcount, 2);
-        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);
+        init_imp_at(&imp->imp_at);
 
-        /* the default magic is V1, will be used in connect RPC, and
+        /* the default magic is V2, will be used in connect RPC, and
          * then adjusted according to the flags in request/reply. */
-        imp->imp_msg_magic = LUSTRE_MSG_MAGIC_V1;
+        imp->imp_msg_magic = LUSTRE_MSG_MAGIC_V2;
 
         return imp;
 }
@@ -876,13 +997,56 @@ void class_destroy_import(struct obd_import *import)
 
         class_handle_unhash(&import->imp_handle);
 
-        spin_lock(&import->imp_lock);
+        cfs_spin_lock(&import->imp_lock);
         import->imp_generation++;
-        spin_unlock(&import->imp_lock);
+        cfs_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)
+{
+        cfs_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);
+        cfs_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)
+{
+        cfs_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);
+        cfs_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
@@ -914,36 +1078,41 @@ void class_export_recovery_cleanup(struct obd_export *exp)
 {
         struct obd_device *obd = exp->exp_obd;
 
-        spin_lock_bh(&obd->obd_processing_task_lock);
+        cfs_spin_lock(&obd->obd_recovery_task_lock);
+        if (exp->exp_delayed)
+                obd->obd_delayed_clients--;
         if (obd->obd_recovering && exp->exp_in_recovery) {
-                spin_lock(&exp->exp_lock);
+                cfs_spin_lock(&exp->exp_lock);
                 exp->exp_in_recovery = 0;
-                spin_unlock(&exp->exp_lock);
+                cfs_spin_unlock(&exp->exp_lock);
+                LASSERT(obd->obd_connected_clients);
                 obd->obd_connected_clients--;
-                /* each connected client is counted as recoverable */
-                obd->obd_recoverable_clients--;
-                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);
-                }
-                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);
+        cfs_spin_unlock(&obd->obd_recovery_task_lock);
+        /** Cleanup req replay fields */
+        if (exp->exp_req_replay_needed) {
+                cfs_spin_lock(&exp->exp_lock);
+                exp->exp_req_replay_needed = 0;
+                cfs_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) {
+                cfs_spin_lock(&exp->exp_lock);
+                exp->exp_lock_replay_needed = 0;
+                cfs_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 two references from the export: one for the
- * hash entry and one for the export pointer passed in.  The export
- * pointer passed to this function is destroyed should not be used
- * again. */
+/* This function removes 1-3 references from the export:
+ * 1 - for export pointer passed
+ * and if disconnect really need
+ * 2 - removing from hash
+ * 3 - in client_unlink_export
+ * The export pointer passed to this function can destroyed */
 int class_disconnect(struct obd_export *export)
 {
         int already_disconnected;
@@ -955,47 +1124,66 @@ int class_disconnect(struct obd_export *export)
                 RETURN(-EINVAL);
         }
 
-        spin_lock(&export->exp_lock);
+        cfs_spin_lock(&export->exp_lock);
         already_disconnected = export->exp_disconnected;
         export->exp_disconnected = 1;
-
-        if (!hlist_unhashed(&export->exp_nid_hash)) {
-                lustre_hash_delitem(export->exp_obd->obd_nid_hash_body,
-                                    &export->exp_connection->c_peer.nid, &export->exp_nid_hash);
-        }
-        spin_unlock(&export->exp_lock);
+        cfs_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)
-                RETURN(0);
+        if (already_disconnected) {
+                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 (!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);
+no_disconn:
         class_export_put(export);
         RETURN(0);
 }
 
-static void class_disconnect_export_list(struct list_head *list, int flags)
+/* Return non-zero for a fully connected export */
+int class_connected_export(struct obd_export *exp)
+{
+        if (exp) {
+                int connected;
+                cfs_spin_lock(&exp->exp_lock);
+                connected = (exp->exp_conn_cnt > 0);
+                cfs_spin_unlock(&exp->exp_lock);
+                return connected;
+        }
+        return 0;
+}
+EXPORT_SYMBOL(class_connected_export);
+
+static void class_disconnect_export_list(cfs_list_t *list,
+                                         enum obd_option flags)
 {
         int rc;
-        struct lustre_handle fake_conn;
-        struct obd_export *fake_exp, *exp;
+        struct obd_export *exp;
         ENTRY;
 
         /* 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);
+                cfs_spin_lock(&exp->exp_lock);
                 exp->exp_flags = flags;
-                spin_unlock(&exp->exp_lock);
+                cfs_spin_unlock(&exp->exp_lock);
 
                 if (obd_uuid_equals(&exp->exp_client_uuid,
                                     &exp->exp_obd->obd_uuid)) {
@@ -1004,52 +1192,43 @@ static void class_disconnect_export_list(struct list_head *list, int flags)
                                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);
-                        class_export_put(exp);
-                        continue;
-                }
-
-                fake_conn.cookie = exp->exp_handle.h_cookie;
-                fake_exp = class_conn2export(&fake_conn);
-                if (!fake_exp) {
+                        cfs_list_del_init(&exp->exp_obd_chain);
                         class_export_put(exp);
                         continue;
                 }
 
-                spin_lock(&fake_exp->exp_lock);
-                fake_exp->exp_flags = flags;
-                spin_unlock(&fake_exp->exp_lock);
-
-                rc = obd_disconnect(fake_exp);
+                class_export_get(exp);
+                CDEBUG(D_HA, "%s: disconnecting export at %s (%p), "
+                       "last request at "CFS_TIME_T"\n",
+                       exp->exp_obd->obd_name, obd_export_nid2str(exp),
+                       exp, exp->exp_last_request_time);
+                /* release one export reference anyway */
+                rc = obd_disconnect(exp);
+
+                CDEBUG(D_HA, "disconnected export at %s (%p): rc %d\n",
+                       obd_export_nid2str(exp), exp, rc);
                 class_export_put(exp);
-                CDEBUG(D_HA, "disconnecting export %s (%p): rc %d\n",
-                       exp->exp_client_uuid.uuid, exp, rc);
         }
         EXIT;
 }
 
-static inline int get_exp_flags_from_obd(struct obd_device *obd)
-{
-        return ((obd->obd_fail ? OBD_OPT_FAILOVER : 0) |
-                (obd->obd_force ? OBD_OPT_FORCE : 0));
-}
-
 void class_disconnect_exports(struct obd_device *obd)
 {
-        struct list_head work_list;
+        cfs_list_t work_list;
         ENTRY;
 
         /* Move all of the exports from obd_exports to a work list, en masse. */
-        spin_lock(&obd->obd_dev_lock);
-        list_add(&work_list, &obd->obd_exports);
-        list_del_init(&obd->obd_exports);
-        spin_unlock(&obd->obd_dev_lock);
-        
-        if (!list_empty(&work_list)) {
+        CFS_INIT_LIST_HEAD(&work_list);
+        cfs_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);
+        cfs_spin_unlock(&obd->obd_dev_lock);
+
+        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, 
-                                             get_exp_flags_from_obd(obd));
+                class_disconnect_export_list(&work_list,
+                                             exp_flags_from_obd(obd));
         } else
                 CDEBUG(D_HA, "OBD device %d (%p) has no exports\n",
                        obd->obd_minor, obd);
@@ -1059,192 +1238,56 @@ EXPORT_SYMBOL(class_disconnect_exports);
 
 /* Remove exports that have not completed recovery.
  */
-int class_disconnect_stale_exports(struct obd_device *obd,
-                                   int (*test_export)(struct obd_export *))
+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;
+        cfs_list_t work_list;
+        cfs_list_t *pos, *n;
         struct obd_export *exp;
-        int cnt = 0;
+        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);
+        cfs_spin_lock(&obd->obd_dev_lock);
+        cfs_list_for_each_safe(pos, n, &obd->obd_exports) {
+                exp = cfs_list_entry(pos, struct obd_export, exp_obd_chain);
                 if (test_export(exp))
                         continue;
-                
-                list_del(&exp->exp_obd_chain);
-                list_add(&exp->exp_obd_chain, &work_list);
+
                 /* don't count self-export as client */
                 if (obd_uuid_equals(&exp->exp_client_uuid,
-                                     &exp->exp_obd->obd_uuid))
+                                    &exp->exp_obd->obd_uuid))
                         continue;
 
-                cnt++;
+                cfs_list_move(&exp->exp_obd_chain, &work_list);
+                evicted++;
                 CDEBUG(D_ERROR, "%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", 0);
         }
-        spin_unlock(&obd->obd_dev_lock);
-
-        CDEBUG(D_ERROR, "%s: disconnecting %d stale clients\n",
-               obd->obd_name, cnt);
-        class_disconnect_export_list(&work_list, get_exp_flags_from_obd(obd));
-        RETURN(cnt);
-}
-EXPORT_SYMBOL(class_disconnect_stale_exports);
+        cfs_spin_unlock(&obd->obd_dev_lock);
 
-int oig_init(struct obd_io_group **oig_out)
-{
-        struct obd_io_group *oig;
-        ENTRY;
-
-        OBD_ALLOC(oig, sizeof(*oig));
-        if (oig == NULL)
-                RETURN(-ENOMEM);
-
-        spin_lock_init(&oig->oig_lock);
-        oig->oig_rc = 0;
-        oig->oig_pending = 0;
-        atomic_set(&oig->oig_refcount, 1);
-        cfs_waitq_init(&oig->oig_waitq);
-        CFS_INIT_LIST_HEAD(&oig->oig_occ_list);
-
-        *oig_out = oig;
-        RETURN(0);
-};
-EXPORT_SYMBOL(oig_init);
-
-static inline void oig_grab(struct obd_io_group *oig)
-{
-        atomic_inc(&oig->oig_refcount);
-}
-
-void oig_release(struct obd_io_group *oig)
-{
-        if (atomic_dec_and_test(&oig->oig_refcount))
-                OBD_FREE(oig, sizeof(*oig));
-}
-EXPORT_SYMBOL(oig_release);
-
-int oig_add_one(struct obd_io_group *oig, struct oig_callback_context *occ)
-{
-        int rc = 0;
-        CDEBUG(D_CACHE, "oig %p ready to roll\n", oig);
-        spin_lock(&oig->oig_lock);
-        if (oig->oig_rc) {
-                rc = oig->oig_rc;
-        } else {
-                oig->oig_pending++;
-                if (occ != NULL)
-                        list_add_tail(&occ->occ_oig_item, &oig->oig_occ_list);
-        }
-        spin_unlock(&oig->oig_lock);
-        oig_grab(oig);
-
-        return rc;
-}
-EXPORT_SYMBOL(oig_add_one);
-
-void oig_complete_one(struct obd_io_group *oig,
-                      struct oig_callback_context *occ, int rc)
-{
-        cfs_waitq_t *wake = NULL;
-        int old_rc;
-
-        spin_lock(&oig->oig_lock);
-
-        if (occ != NULL)
-                list_del_init(&occ->occ_oig_item);
-
-        old_rc = oig->oig_rc;
-        if (oig->oig_rc == 0 && rc != 0)
-                oig->oig_rc = rc;
-
-        if (--oig->oig_pending <= 0)
-                wake = &oig->oig_waitq;
-
-        spin_unlock(&oig->oig_lock);
-
-        CDEBUG(D_CACHE, "oig %p completed, rc %d -> %d via %d, %d now "
-                        "pending (racey)\n", oig, old_rc, oig->oig_rc, rc,
-                        oig->oig_pending);
-        if (wake)
-                cfs_waitq_signal(wake);
-        oig_release(oig);
-}
-EXPORT_SYMBOL(oig_complete_one);
-
-static int oig_done(struct obd_io_group *oig)
-{
-        int rc = 0;
-        spin_lock(&oig->oig_lock);
-        if (oig->oig_pending <= 0)
-                rc = 1;
-        spin_unlock(&oig->oig_lock);
-        return rc;
-}
-
-static void interrupted_oig(void *data)
-{
-        struct obd_io_group *oig = data;
-        struct oig_callback_context *occ;
-
-        spin_lock(&oig->oig_lock);
-        /* We need to restart the processing each time we drop the lock, as
-         * it is possible other threads called oig_complete_one() to remove
-         * an entry elsewhere in the list while we dropped lock.  We need to
-         * drop the lock because osc_ap_completion() calls oig_complete_one()
-         * which re-gets this lock ;-) as well as a lock ordering issue. */
-restart:
-        list_for_each_entry(occ, &oig->oig_occ_list, occ_oig_item) {
-                if (occ->interrupted)
-                        continue;
-                occ->interrupted = 1;
-                spin_unlock(&oig->oig_lock);
-                occ->occ_interrupted(occ);
-                spin_lock(&oig->oig_lock);
-                goto restart;
+        if (evicted) {
+                CDEBUG(D_HA, "%s: disconnecting %d stale clients\n",
+                       obd->obd_name, evicted);
+                obd->obd_stale_clients += evicted;
         }
-        spin_unlock(&oig->oig_lock);
-}
-
-int oig_wait(struct obd_io_group *oig)
-{
-        struct l_wait_info lwi = LWI_INTR(interrupted_oig, oig);
-        int rc;
-
-        CDEBUG(D_CACHE, "waiting for oig %p\n", oig);
-
-        do {
-                rc = l_wait_event(oig->oig_waitq, oig_done(oig), &lwi);
-                LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
-                /* we can't continue until the oig has emptied and stopped
-                 * referencing state that the caller will free upon return */
-                if (rc == -EINTR)
-                        lwi = (struct l_wait_info){ 0, };
-        } while (rc == -EINTR);
-
-        LASSERTF(oig->oig_pending == 0,
-                 "exiting oig_wait(oig = %p) with %d pending\n", oig,
-                 oig->oig_pending);
-
-        CDEBUG(D_CACHE, "done waiting on oig %p rc %d\n", oig, oig->oig_rc);
-        return oig->oig_rc;
+        class_disconnect_export_list(&work_list, exp_flags_from_obd(obd) |
+                                                 OBD_OPT_ABORT_RECOV);
+        EXIT;
 }
-EXPORT_SYMBOL(oig_wait);
+EXPORT_SYMBOL(class_disconnect_stale_exports);
 
 void class_fail_export(struct obd_export *exp)
 {
         int rc, already_failed;
 
-        spin_lock(&exp->exp_lock);
+        cfs_spin_lock(&exp->exp_lock);
         already_failed = exp->exp_failed;
         exp->exp_failed = 1;
-        spin_unlock(&exp->exp_lock);
+        cfs_spin_unlock(&exp->exp_lock);
 
         if (already_failed) {
                 CDEBUG(D_HA, "disconnecting dead export %p/%s; skipping\n",
@@ -1285,18 +1328,17 @@ 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(nid);
+        lnet_nid_t nid_key = libcfs_str2nid((char *)nid);
 
         do {
-                doomed_exp = lustre_hash_get_object_by_key(obd->obd_nid_hash_body,
-                                                           &nid_key);
+                doomed_exp = cfs_hash_lookup(obd->obd_nid_hash, &nid_key);
                 if (doomed_exp == NULL)
                         break;
 
                 LASSERTF(doomed_exp->exp_connection->c_peer.nid == nid_key,
                          "nid %s found, wanted nid %s, requested nid %s\n",
                          obd_export_nid2str(doomed_exp),
-                         libcfs_nid2str(nid_key), nid);        
+                         libcfs_nid2str(nid_key), nid);
                 LASSERTF(doomed_exp != obd->obd_self_export,
                          "self-export is hashed by NID?\n");
                 exports_evicted++;
@@ -1317,17 +1359,16 @@ 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;
+        struct obd_uuid doomed_uuid;
         int exports_evicted = 0;
 
-        obd_str2uuid(&doomed, uuid);
-        if (obd_uuid_equals(&doomed, &obd->obd_uuid)) {
+        obd_str2uuid(&doomed_uuid, uuid);
+        if (obd_uuid_equals(&doomed_uuid, &obd->obd_uuid)) {
                 CERROR("%s: can't evict myself\n", obd->obd_name);
                 return exports_evicted;
         }
 
-        doomed_exp = lustre_hash_get_object_by_key(obd->obd_uuid_hash_body, 
-                                                   &doomed);
+        doomed_exp = cfs_hash_lookup(obd->obd_uuid_hash, &doomed_uuid);
 
         if (doomed_exp == NULL) {
                 CERROR("%s: can't disconnect %s: no exports found\n",
@@ -1344,48 +1385,390 @@ int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
 }
 EXPORT_SYMBOL(obd_export_evict_by_uuid);
 
-void obd_zombie_impexp_cull(void) 
+#if LUSTRE_TRACKS_LOCK_EXP_REFS
+void (*class_export_dump_hook)(struct obd_export*) = NULL;
+EXPORT_SYMBOL(class_export_dump_hook);
+#endif
+
+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;
+
+        cfs_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++;
+        }
+        cfs_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), 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, int locks)
+{
+        struct obd_export *exp;
+
+        cfs_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);
+        cfs_spin_unlock(&obd->obd_dev_lock);
+        cfs_spin_lock(&obd_zombie_impexp_lock);
+        cfs_list_for_each_entry(exp, &obd_zombie_exports, exp_obd_chain)
+                print_export_data(exp, "ZOMBIE", locks);
+        cfs_spin_unlock(&obd_zombie_impexp_lock);
+}
+EXPORT_SYMBOL(dump_exports);
+
+void obd_exports_barrier(struct obd_device *obd)
+{
+        int waited = 2;
+        LASSERT(cfs_list_empty(&obd->obd_exports));
+        cfs_spin_lock(&obd->obd_dev_lock);
+        while (!cfs_list_empty(&obd->obd_unlinked_exports)) {
+                cfs_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,
+                                      cfs_atomic_read(&obd->obd_refcount));
+                        dump_exports(obd, 1);
+                }
+                waited *= 2;
+                cfs_spin_lock(&obd->obd_dev_lock);
+        }
+        cfs_spin_unlock(&obd->obd_dev_lock);
+}
+EXPORT_SYMBOL(obd_exports_barrier);
+
+/**
+ * kill zombie imports and exports
+ */
+void obd_zombie_impexp_cull(void)
 {
         struct obd_import *import;
         struct obd_export *export;
         ENTRY;
-        
+
         do {
-                spin_lock (&obd_zombie_impexp_lock);
+                cfs_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(&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);
-                
+                cfs_spin_unlock(&obd_zombie_impexp_lock);
+
                 if (import != NULL)
                         class_import_destroy(import);
 
                 if (export != NULL)
                         class_export_destroy(export);
 
+                cfs_cond_resched();
         } while (import != NULL || export != NULL);
         EXIT;
 }
-EXPORT_SYMBOL(obd_zombie_impexp_cull);
 
-void obd_zombie_impexp_init(void)
+static cfs_completion_t         obd_zombie_start;
+static cfs_completion_t         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
+};
+
+/**
+ * check for work for kill zombie import/export thread.
+ */
+static int obd_zombie_impexp_check(void *arg)
+{
+        int rc;
+
+        cfs_spin_lock(&obd_zombie_impexp_lock);
+        rc = cfs_list_empty(&obd_zombie_imports) &&
+             cfs_list_empty(&obd_zombie_exports) &&
+             !cfs_test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+
+        cfs_spin_unlock(&obd_zombie_impexp_lock);
+
+        RETURN(rc);
+}
+
+/**
+ * Add export to the obd_zombe thread and notify it.
+ */
+static void obd_zombie_export_add(struct obd_export *exp) {
+        cfs_spin_lock(&exp->exp_obd->obd_dev_lock);
+        LASSERT(!cfs_list_empty(&exp->exp_obd_chain));
+        cfs_list_del_init(&exp->exp_obd_chain);
+        cfs_spin_unlock(&exp->exp_obd->obd_dev_lock);
+        cfs_spin_lock(&obd_zombie_impexp_lock);
+        cfs_list_add(&exp->exp_obd_chain, &obd_zombie_exports);
+        cfs_spin_unlock(&obd_zombie_impexp_lock);
+
+        if (obd_zombie_impexp_notify != NULL)
+                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);
+        cfs_spin_lock(&obd_zombie_impexp_lock);
+        LASSERT(cfs_list_empty(&imp->imp_zombie_chain));
+        cfs_list_add(&imp->imp_zombie_chain, &obd_zombie_imports);
+        cfs_spin_unlock(&obd_zombie_impexp_lock);
+
+        if (obd_zombie_impexp_notify != NULL)
+                obd_zombie_impexp_notify();
+}
+
+/**
+ * notify import/export destroy thread about new zombie.
+ */
+static void obd_zombie_impexp_notify(void)
 {
-        INIT_LIST_HEAD(&obd_zombie_imports);
-        INIT_LIST_HEAD(&obd_zombie_exports);
-        spin_lock_init(&obd_zombie_impexp_lock);
+        cfs_waitq_signal(&obd_zombie_waitq);
 }
 
+/**
+ * check whether obd_zombie is idle
+ */
+static int obd_zombie_is_idle(void)
+{
+        int rc;
+
+        LASSERT(!cfs_test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags));
+        cfs_spin_lock(&obd_zombie_impexp_lock);
+        rc = cfs_list_empty(&obd_zombie_imports) &&
+             cfs_list_empty(&obd_zombie_exports);
+        cfs_spin_unlock(&obd_zombie_impexp_lock);
+        return rc;
+}
+
+/**
+ * wait when obd_zombie import/export queues become empty
+ */
+void obd_zombie_barrier(void)
+{
+        struct l_wait_info lwi = { 0 };
+
+        if (obd_zombie_pid == cfs_curproc_pid())
+                /* don't wait for myself */
+                return;
+        l_wait_event(obd_zombie_waitq, obd_zombie_is_idle(), &lwi);
+}
+EXPORT_SYMBOL(obd_zombie_barrier);
+
+#ifdef __KERNEL__
+
+/**
+ * destroy zombie export/import thread.
+ */
+static int obd_zombie_impexp_thread(void *unused)
+{
+        int rc;
+
+        if ((rc = cfs_daemonize_ctxt("obd_zombid"))) {
+                cfs_complete(&obd_zombie_start);
+                RETURN(rc);
+        }
+
+        cfs_complete(&obd_zombie_start);
+
+        obd_zombie_pid = cfs_curproc_pid();
+
+        while(!cfs_test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags)) {
+                struct l_wait_info lwi = { 0 };
+
+                l_wait_event(obd_zombie_waitq,
+                             !obd_zombie_impexp_check(NULL), &lwi);
+                obd_zombie_impexp_cull();
+
+                /*
+                 * Notify obd_zombie_barrier callers that queues
+                 * may be empty.
+                 */
+                cfs_waitq_signal(&obd_zombie_waitq);
+        }
+
+        cfs_complete(&obd_zombie_stop);
+
+        RETURN(0);
+}
+
+#else /* ! KERNEL */
+
+static cfs_atomic_t zombie_recur = CFS_ATOMIC_INIT(0);
+static void *obd_zombie_impexp_work_cb;
+static void *obd_zombie_impexp_idle_cb;
+
+int obd_zombie_impexp_kill(void *arg)
+{
+        int rc = 0;
+
+        if (cfs_atomic_inc_return(&zombie_recur) == 1) {
+                obd_zombie_impexp_cull();
+                rc = 1;
+        }
+        cfs_atomic_dec(&zombie_recur);
+        return rc;
+}
+
+#endif
+
+/**
+ * start destroy zombie import/export thread
+ */
+int obd_zombie_impexp_init(void)
+{
+        int rc;
+
+        CFS_INIT_LIST_HEAD(&obd_zombie_imports);
+        CFS_INIT_LIST_HEAD(&obd_zombie_exports);
+        cfs_spin_lock_init(&obd_zombie_impexp_lock);
+        cfs_init_completion(&obd_zombie_start);
+        cfs_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);
+
+        cfs_wait_for_completion(&obd_zombie_start);
+#else
+
+        obd_zombie_impexp_work_cb =
+                liblustre_register_wait_callback("obd_zombi_impexp_kill",
+                                                 &obd_zombie_impexp_kill, NULL);
+
+        obd_zombie_impexp_idle_cb =
+                liblustre_register_idle_callback("obd_zombi_impexp_check",
+                                                 &obd_zombie_impexp_check, NULL);
+        rc = 0;
+#endif
+        RETURN(rc);
+}
+/**
+ * stop destroy zombie import/export thread
+ */
+void obd_zombie_impexp_stop(void)
+{
+        cfs_set_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+        obd_zombie_impexp_notify();
+#ifdef __KERNEL__
+        cfs_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);
+
+
+