X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fstaging%2Flustre%2Flustre%2Fobdclass%2Fgenops.c;fp=kernel%2Fdrivers%2Fstaging%2Flustre%2Flustre%2Fobdclass%2Fgenops.c;h=66b56784f674e21c049e499bd2d03b8e3d38e6ca;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/staging/lustre/lustre/obdclass/genops.c b/kernel/drivers/staging/lustre/lustre/obdclass/genops.c
new file mode 100644
index 000000000..66b56784f
--- /dev/null
+++ b/kernel/drivers/staging/lustre/lustre/obdclass/genops.c
@@ -0,0 +1,1833 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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.
+ *
+ * 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).
+ *
+ * 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.
+ *
+ * Copyright (c) 2011, 2012, Intel Corporation.
+ */
+/*
+ * 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
+ */
+
+#define DEBUG_SUBSYSTEM S_CLASS
+#include "../include/obd_class.h"
+#include "../include/lprocfs_status.h"
+
+spinlock_t obd_types_lock;
+
+struct kmem_cache *obd_device_cachep;
+struct kmem_cache *obdo_cachep;
+EXPORT_SYMBOL(obdo_cachep);
+static struct kmem_cache *import_cachep;
+
+static struct list_head      obd_zombie_imports;
+static struct list_head      obd_zombie_exports;
+static 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);
+EXPORT_SYMBOL(ptlrpc_put_connection_superhack);
+
+/*
+ * support functions: we could use inter-module communication, but this
+ * is more portable to other OS's
+ */
+static struct obd_device *obd_device_alloc(void)
+{
+	struct obd_device *obd;
+
+	OBD_SLAB_ALLOC_PTR_GFP(obd, obd_device_cachep, GFP_NOFS);
+	if (obd != NULL) {
+		obd->obd_magic = OBD_DEVICE_MAGIC;
+	}
+	return obd;
+}
+
+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",
+		 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);
+}
+
+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;
+}
+EXPORT_SYMBOL(class_search_type);
+
+struct obd_type *class_get_type(const char *name)
+{
+	struct obd_type *type = class_search_type(name);
+
+	if (!type) {
+		const char *modname = name;
+
+		if (strcmp(modname, "obdfilter") == 0)
+			modname = "ofd";
+
+		if (strcmp(modname, LUSTRE_LWP_NAME) == 0)
+			modname = LUSTRE_OSP_NAME;
+
+		if (!strncmp(modname, LUSTRE_MDS_NAME, strlen(LUSTRE_MDS_NAME)))
+			modname = LUSTRE_MDT_NAME;
+
+		if (!request_module("%s", modname)) {
+			CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
+			type = class_search_type(name);
+		} else {
+			LCONSOLE_ERROR_MSG(0x158, "Can't load module '%s'\n",
+					   modname);
+		}
+	}
+	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;
+}
+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);
+}
+EXPORT_SYMBOL(class_put_type);
+
+#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,
+			struct lu_device_type *ldt)
+{
+	struct obd_type *type;
+	int rc = 0;
+
+	/* sanity check */
+	LASSERT(strnlen(name, CLASS_MAX_NAME) < CLASS_MAX_NAME);
+
+	if (class_search_type(name)) {
+		CDEBUG(D_IOCTL, "Type %s already registered\n", name);
+		return -EEXIST;
+	}
+
+	rc = -ENOMEM;
+	OBD_ALLOC(type, sizeof(*type));
+	if (type == NULL)
+		return rc;
+
+	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 ||
+	    type->typ_name == NULL)
+		goto failed;
+
+	*(type->typ_dt_ops) = *dt_ops;
+	/* md_ops is optional */
+	if (md_ops)
+		*(type->typ_md_ops) = *md_ops;
+	strcpy(type->typ_name, name);
+	spin_lock_init(&type->obd_type_lock);
+
+	type->typ_procroot = lprocfs_register(type->typ_name, proc_lustre_root,
+					      vars, type);
+	if (IS_ERR(type->typ_procroot)) {
+		rc = PTR_ERR(type->typ_procroot);
+		type->typ_procroot = NULL;
+		goto failed;
+	}
+
+	if (ldt != NULL) {
+		type->typ_lu = ldt;
+		rc = lu_device_type_init(ldt);
+		if (rc != 0)
+			goto failed;
+	}
+
+	spin_lock(&obd_types_lock);
+	list_add(&type->typ_chain, &obd_types);
+	spin_unlock(&obd_types_lock);
+
+	return 0;
+
+ failed:
+	if (type->typ_name != NULL)
+		OBD_FREE(type->typ_name, strlen(name) + 1);
+	if (type->typ_md_ops != NULL)
+		OBD_FREE_PTR(type->typ_md_ops);
+	if (type->typ_dt_ops != NULL)
+		OBD_FREE_PTR(type->typ_dt_ops);
+	OBD_FREE(type, sizeof(*type));
+	return rc;
+}
+EXPORT_SYMBOL(class_register_type);
+
+int class_unregister_type(const char *name)
+{
+	struct obd_type *type = class_search_type(name);
+
+	if (!type) {
+		CERROR("unknown obd type\n");
+		return -EINVAL;
+	}
+
+	if (type->typ_refcnt) {
+		CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt);
+		/* This is a bad situation, let's make the best of it */
+		/* Remove ops, but leave the name for debugging */
+		OBD_FREE_PTR(type->typ_dt_ops);
+		OBD_FREE_PTR(type->typ_md_ops);
+		return -EBUSY;
+	}
+
+	if (type->typ_procroot) {
+		lprocfs_remove(&type->typ_procroot);
+	}
+
+	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);
+	OBD_FREE(type->typ_name, strlen(name) + 1);
+	if (type->typ_dt_ops != NULL)
+		OBD_FREE_PTR(type->typ_dt_ops);
+	if (type->typ_md_ops != NULL)
+		OBD_FREE_PTR(type->typ_md_ops);
+	OBD_FREE(type, sizeof(*type));
+	return 0;
+} /* class_unregister_type */
+EXPORT_SYMBOL(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;
+	struct obd_device *newdev;
+	struct obd_type *type = NULL;
+	int i;
+	int new_obd_minor = 0;
+
+	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);
+	if (type == NULL){
+		CERROR("OBD: unknown type: %s\n", type_name);
+		return ERR_PTR(-ENODEV);
+	}
+
+	newdev = obd_device_alloc();
+	if (newdev == NULL) {
+		result = ERR_PTR(-ENOMEM);
+		goto out_type;
+	}
+
+	LASSERT(newdev->obd_magic == OBD_DEVICE_MAGIC);
+
+	write_lock(&obd_dev_lock);
+	for (i = 0; i < class_devno_max(); i++) {
+		struct obd_device *obd = class_num2obd(i);
+
+		if (obd && (strcmp(name, obd->obd_name) == 0)) {
+			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,
+					 result->obd_magic, OBD_DEVICE_MAGIC);
+				LASSERTF(result->obd_minor == new_obd_minor,
+					 "%p obd_minor %d != %d\n", result,
+					 result->obd_minor, new_obd_minor);
+
+				obd_devs[result->obd_minor] = NULL;
+				result->obd_name[0] = '\0';
+			 }
+			result = ERR_PTR(-EEXIST);
+			break;
+		}
+		if (!result && !obd) {
+			result = newdev;
+			result->obd_minor = i;
+			new_obd_minor = i;
+			result->obd_type = type;
+			strncpy(result->obd_name, name,
+				sizeof(result->obd_name) - 1);
+			obd_devs[i] = result;
+		}
+	}
+	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;
+	}
+
+	if (IS_ERR(result))
+		goto out;
+
+	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)
+{
+	struct obd_type *obd_type = obd->obd_type;
+
+	LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "%p obd_magic %08x != %08x\n",
+		 obd, obd->obd_magic, OBD_DEVICE_MAGIC);
+	LASSERTF(obd == obd_devs[obd->obd_minor], "obd %p != obd_devs[%d] %p\n",
+		 obd, obd->obd_minor, obd_devs[obd->obd_minor]);
+	LASSERT(obd_type != NULL);
+
+	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);
+
+	write_lock(&obd_dev_lock);
+	obd_devs[obd->obd_minor] = NULL;
+	write_unlock(&obd_dev_lock);
+	obd_device_free(obd);
+
+	class_put_type(obd_type);
+}
+
+int class_name2dev(const char *name)
+{
+	int i;
+
+	if (!name)
+		return -1;
+
+	read_lock(&obd_dev_lock);
+	for (i = 0; i < class_devno_max(); i++) {
+		struct obd_device *obd = class_num2obd(i);
+
+		if (obd && 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) {
+				read_unlock(&obd_dev_lock);
+				return i;
+			}
+			break;
+		}
+	}
+	read_unlock(&obd_dev_lock);
+
+	return -1;
+}
+EXPORT_SYMBOL(class_name2dev);
+
+struct obd_device *class_name2obd(const char *name)
+{
+	int dev = class_name2dev(name);
+
+	if (dev < 0 || dev > class_devno_max())
+		return NULL;
+	return class_num2obd(dev);
+}
+EXPORT_SYMBOL(class_name2obd);
+
+int class_uuid2dev(struct obd_uuid *uuid)
+{
+	int i;
+
+	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);
+			read_unlock(&obd_dev_lock);
+			return i;
+		}
+	}
+	read_unlock(&obd_dev_lock);
+
+	return -1;
+}
+EXPORT_SYMBOL(class_uuid2dev);
+
+struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
+{
+	int dev = class_uuid2dev(uuid);
+	if (dev < 0)
+		return NULL;
+	return class_num2obd(dev);
+}
+EXPORT_SYMBOL(class_uuid2obd);
+
+/**
+ * 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)
+			return NULL;
+
+		LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC,
+			 "%p obd_magic %08x != %08x\n",
+			 obd, obd->obd_magic, OBD_DEVICE_MAGIC);
+		LASSERTF(obd->obd_minor == num,
+			 "%p obd_minor %0d != %0d\n",
+			 obd, obd->obd_minor, num);
+	}
+
+	return obd;
+}
+EXPORT_SYMBOL(class_num2obd);
+
+/**
+ * Get obd devices count. Device in any
+ *    state are counted
+ * \retval obd device count
+ */
+int get_devices_count(void)
+{
+	int index, max_index = class_devno_max(), dev_count = 0;
+
+	read_lock(&obd_dev_lock);
+	for (index = 0; index <= max_index; index++) {
+		struct obd_device *obd = class_num2obd(index);
+		if (obd != NULL)
+			dev_count++;
+	}
+	read_unlock(&obd_dev_lock);
+
+	return dev_count;
+}
+EXPORT_SYMBOL(get_devices_count);
+
+void class_obd_list(void)
+{
+	char *status;
+	int i;
+
+	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)
+			status = "ST";
+		else if (obd->obd_set_up)
+			status = "UP";
+		else if (obd->obd_attached)
+			status = "AT";
+		else
+			status = "--";
+		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));
+	}
+	read_unlock(&obd_dev_lock);
+	return;
+}
+
+/* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
+   specified, then only the client with that uuid is returned,
+   otherwise any client connected to the tgt is returned. */
+struct obd_device *class_find_client_obd(struct obd_uuid *tgt_uuid,
+					  const char *typ_name,
+					  struct obd_uuid *grp_uuid)
+{
+	int i;
+
+	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,
+			     strlen(typ_name)) == 0)) {
+			if (obd_uuid_equals(tgt_uuid,
+					    &obd->u.cli.cl_target_uuid) &&
+			    ((grp_uuid)? obd_uuid_equals(grp_uuid,
+							 &obd->obd_uuid) : 1)) {
+				read_unlock(&obd_dev_lock);
+				return obd;
+			}
+		}
+	}
+	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
+   at is saved in *next. If next is NULL, then the first matching device
+   will always be returned. */
+struct obd_device *class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
+{
+	int i;
+
+	if (next == NULL)
+		i = 0;
+	else if (*next >= 0 && *next < class_devno_max())
+		i = *next;
+	else
+		return NULL;
+
+	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;
+			read_unlock(&obd_dev_lock);
+			return obd;
+		}
+	}
+	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
+ * 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);
+
+	read_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, __func__, obd);
+		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, __func__, obd);
+		read_lock(&obd_dev_lock);
+	}
+	read_unlock(&obd_dev_lock);
+	return rc;
+}
+EXPORT_SYMBOL(class_notify_sptlrpc_conf);
+
+void obd_cleanup_caches(void)
+{
+	if (obd_device_cachep) {
+		kmem_cache_destroy(obd_device_cachep);
+		obd_device_cachep = NULL;
+	}
+	if (obdo_cachep) {
+		kmem_cache_destroy(obdo_cachep);
+		obdo_cachep = NULL;
+	}
+	if (import_cachep) {
+		kmem_cache_destroy(import_cachep);
+		import_cachep = NULL;
+	}
+	if (capa_cachep) {
+		kmem_cache_destroy(capa_cachep);
+		capa_cachep = NULL;
+	}
+}
+
+int obd_init_caches(void)
+{
+	LASSERT(obd_device_cachep == NULL);
+	obd_device_cachep = kmem_cache_create("ll_obd_dev_cache",
+						 sizeof(struct obd_device),
+						 0, 0, NULL);
+	if (!obd_device_cachep)
+		goto out;
+
+	LASSERT(obdo_cachep == NULL);
+	obdo_cachep = kmem_cache_create("ll_obdo_cache", sizeof(struct obdo),
+					   0, 0, NULL);
+	if (!obdo_cachep)
+		goto out;
+
+	LASSERT(import_cachep == NULL);
+	import_cachep = kmem_cache_create("ll_import_cache",
+					     sizeof(struct obd_import),
+					     0, 0, NULL);
+	if (!import_cachep)
+		goto out;
+
+	LASSERT(capa_cachep == NULL);
+	capa_cachep = kmem_cache_create("capa_cache",
+					   sizeof(struct obd_capa), 0, 0, NULL);
+	if (!capa_cachep)
+		goto out;
+
+	return 0;
+ out:
+	obd_cleanup_caches();
+	return -ENOMEM;
+
+}
+
+/* map connection to client */
+struct obd_export *class_conn2export(struct lustre_handle *conn)
+{
+	struct obd_export *export;
+
+	if (!conn) {
+		CDEBUG(D_CACHE, "looking for null handle\n");
+		return NULL;
+	}
+
+	if (conn->cookie == -1) {  /* this means assign a new connection */
+		CDEBUG(D_CACHE, "want a new connection\n");
+		return NULL;
+	}
+
+	CDEBUG(D_INFO, "looking for export cookie %#llx\n", conn->cookie);
+	export = class_handle2object(conn->cookie);
+	return export;
+}
+EXPORT_SYMBOL(class_conn2export);
+
+struct obd_device *class_exp2obd(struct obd_export *exp)
+{
+	if (exp)
+		return exp->exp_obd;
+	return NULL;
+}
+EXPORT_SYMBOL(class_exp2obd);
+
+struct obd_device *class_conn2obd(struct lustre_handle *conn)
+{
+	struct obd_export *export;
+	export = class_conn2export(conn);
+	if (export) {
+		struct obd_device *obd = export->exp_obd;
+		class_export_put(export);
+		return obd;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(class_conn2obd);
+
+struct obd_import *class_exp2cliimp(struct obd_export *exp)
+{
+	struct obd_device *obd = exp->exp_obd;
+	if (obd == NULL)
+		return NULL;
+	return obd->u.cli.cl_import;
+}
+EXPORT_SYMBOL(class_exp2cliimp);
+
+struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
+{
+	struct obd_device *obd = class_conn2obd(conn);
+	if (obd == NULL)
+		return NULL;
+	return obd->u.cli.cl_import;
+}
+EXPORT_SYMBOL(class_conn2cliimp);
+
+/* Export management functions */
+static void class_export_destroy(struct obd_export *exp)
+{
+	struct obd_device *obd = exp->exp_obd;
+
+	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);
+
+	/* "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_hp_rpcs));
+	obd_destroy_export(exp);
+	class_decref(obd, "export", exp);
+
+	OBD_FREE_RCU(exp, sizeof(*exp), &exp->exp_handle);
+}
+
+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);
+	CDEBUG(D_INFO, "GETting export %p : new refcount %d\n", exp,
+	       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, LI_POISON);
+	CDEBUG(D_INFO, "PUTting export %p : new refcount %d\n", exp,
+	       atomic_read(&exp->exp_refcount) - 1);
+
+	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);
+
+		/* 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. */
+struct obd_export *class_new_export(struct obd_device *obd,
+				    struct obd_uuid *cluuid)
+{
+	struct obd_export *export;
+	struct cfs_hash *hash = NULL;
+	int rc = 0;
+
+	OBD_ALLOC_PTR(export);
+	if (!export)
+		return ERR_PTR(-ENOMEM);
+
+	export->exp_conn_cnt = 0;
+	export->exp_lock_hash = NULL;
+	export->exp_flock_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);
+#if LUSTRE_TRACKS_LOCK_EXP_REFS
+	INIT_LIST_HEAD(&export->exp_locks_list);
+	spin_lock_init(&export->exp_locks_list_guard);
+#endif
+	atomic_set(&export->exp_replay_count, 0);
+	export->exp_obd = obd;
+	INIT_LIST_HEAD(&export->exp_outstanding_replies);
+	spin_lock_init(&export->exp_uncommitted_replies_lock);
+	INIT_LIST_HEAD(&export->exp_uncommitted_replies);
+	INIT_LIST_HEAD(&export->exp_req_replay_queue);
+	INIT_LIST_HEAD(&export->exp_handle.h_link);
+	INIT_LIST_HEAD(&export->exp_hp_rpcs);
+	class_handle_hash(&export->exp_handle, &export_handle_ops);
+	export->exp_last_request_time = get_seconds();
+	spin_lock_init(&export->exp_lock);
+	spin_lock_init(&export->exp_rpc_lock);
+	INIT_HLIST_NODE(&export->exp_uuid_hash);
+	INIT_HLIST_NODE(&export->exp_nid_hash);
+	spin_lock_init(&export->exp_bl_list_lock);
+	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) {
+		rc = -ENODEV;
+		goto exit_unlock;
+	}
+
+	hash = cfs_hash_getref(obd->obd_uuid_hash);
+	if (hash == NULL) {
+		rc = -ENODEV;
+		goto exit_unlock;
+	}
+	spin_unlock(&obd->obd_dev_lock);
+
+	if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
+		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);
+			rc = -EALREADY;
+			goto exit_err;
+		}
+	}
+
+	spin_lock(&obd->obd_dev_lock);
+	if (obd->obd_stopping) {
+		cfs_hash_del(hash, cluuid, &export->exp_uuid_hash);
+		rc = -ENODEV;
+		goto exit_unlock;
+	}
+
+	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);
+	export->exp_obd->obd_num_exports++;
+	spin_unlock(&obd->obd_dev_lock);
+	cfs_hash_putref(hash);
+	return export;
+
+exit_unlock:
+	spin_unlock(&obd->obd_dev_lock);
+exit_err:
+	if (hash)
+		cfs_hash_putref(hash);
+	class_handle_unhash(&export->exp_handle);
+	LASSERT(hlist_unhashed(&export->exp_uuid_hash));
+	obd_destroy_export(export);
+	OBD_FREE_PTR(export);
+	return ERR_PTR(rc);
+}
+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))
+		cfs_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);
+}
+EXPORT_SYMBOL(class_unlink_export);
+
+/* Import management functions */
+static 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_ZERO(&imp->imp_refcount);
+
+	ptlrpc_put_connection_superhack(imp->imp_connection);
+
+	while (!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);
+		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);
+}
+
+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)
+{
+	atomic_inc(&import->imp_refcount);
+	CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", import,
+	       atomic_read(&import->imp_refcount),
+	       import->imp_obd->obd_name);
+	return import;
+}
+EXPORT_SYMBOL(class_import_get);
+
+void class_import_put(struct obd_import *imp)
+{
+	LASSERT(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,
+	       imp->imp_obd->obd_name);
+
+	if (atomic_dec_and_test(&imp->imp_refcount)) {
+		CDEBUG(D_INFO, "final put import %p\n", imp);
+		obd_zombie_import_add(imp);
+	}
+
+	/* catch possible import put race */
+	LASSERT_ATOMIC_GE_LT(&imp->imp_refcount, 0, LI_POISON);
+}
+EXPORT_SYMBOL(class_import_put);
+
+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);
+	}
+}
+
+struct obd_import *class_new_import(struct obd_device *obd)
+{
+	struct obd_import *imp;
+
+	OBD_ALLOC(imp, sizeof(*imp));
+	if (imp == NULL)
+		return NULL;
+
+	INIT_LIST_HEAD(&imp->imp_pinger_chain);
+	INIT_LIST_HEAD(&imp->imp_zombie_chain);
+	INIT_LIST_HEAD(&imp->imp_replay_list);
+	INIT_LIST_HEAD(&imp->imp_sending_list);
+	INIT_LIST_HEAD(&imp->imp_delayed_list);
+	INIT_LIST_HEAD(&imp->imp_committed_list);
+	imp->imp_replay_cursor = &imp->imp_committed_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);
+	mutex_init(&imp->imp_sec_mutex);
+	init_waitqueue_head(&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);
+	INIT_LIST_HEAD(&imp->imp_conn_list);
+	INIT_LIST_HEAD(&imp->imp_handle.h_link);
+	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
+	 * then adjusted according to the flags in request/reply. */
+	imp->imp_msg_magic = LUSTRE_MSG_MAGIC_V2;
+
+	return imp;
+}
+EXPORT_SYMBOL(class_new_import);
+
+void class_destroy_import(struct obd_import *import)
+{
+	LASSERT(import != NULL);
+	LASSERT(import != LP_POISON);
+
+	class_handle_unhash(&import->imp_handle);
+
+	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) {
+		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) {
+		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
+   returns. */
+int class_connect(struct lustre_handle *conn, struct obd_device *obd,
+		  struct obd_uuid *cluuid)
+{
+	struct obd_export *export;
+	LASSERT(conn != NULL);
+	LASSERT(obd != NULL);
+	LASSERT(cluuid != NULL);
+
+	export = class_new_export(obd, cluuid);
+	if (IS_ERR(export))
+		return PTR_ERR(export);
+
+	conn->cookie = export->exp_handle.h_cookie;
+	class_export_put(export);
+
+	CDEBUG(D_IOCTL, "connect: client %s, cookie %#llx\n",
+	       cluuid->uuid, conn->cookie);
+	return 0;
+}
+EXPORT_SYMBOL(class_connect);
+
+/* if export is involved in recovery then clean up related things */
+static void class_export_recovery_cleanup(struct obd_export *exp)
+{
+	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);
+			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_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT) == 0)
+			exp->exp_obd->obd_stale_clients++;
+	}
+	spin_unlock(&obd->obd_recovery_task_lock);
+
+	spin_lock(&exp->exp_lock);
+	/** Cleanup req replay fields */
+	if (exp->exp_req_replay_needed) {
+		exp->exp_req_replay_needed = 0;
+
+		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) {
+		exp->exp_lock_replay_needed = 0;
+
+		LASSERT(atomic_read(&obd->obd_lock_replay_clients));
+		atomic_dec(&obd->obd_lock_replay_clients);
+	}
+	spin_unlock(&exp->exp_lock);
+}
+
+/* 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;
+
+	if (export == NULL) {
+		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);
+
+	/* 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));
+		goto no_disconn;
+	}
+
+	CDEBUG(D_IOCTL, "disconnect: cookie %#llx\n",
+	       export->exp_handle.h_cookie);
+
+	if (!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;
+}
+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,
+					 enum obd_option flags)
+{
+	int rc;
+	struct obd_export *exp;
+
+	/* 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);
+		/* 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);
+
+		if (obd_uuid_equals(&exp->exp_client_uuid,
+				    &exp->exp_obd->obd_uuid)) {
+			CDEBUG(D_HA,
+			       "exp %p export uuid == obd uuid, don't discon\n",
+			       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;
+		}
+
+		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);
+	}
+}
+
+void class_disconnect_exports(struct obd_device *obd)
+{
+	struct list_head work_list;
+
+	/* Move all of the exports from obd_exports to a work list, en masse. */
+	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);
+
+	if (!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,
+					     exp_flags_from_obd(obd));
+	} else
+		CDEBUG(D_HA, "OBD device %d (%p) has no exports\n",
+		       obd->obd_minor, obd);
+}
+EXPORT_SYMBOL(class_disconnect_exports);
+
+/* Remove exports that have not completed recovery.
+ */
+void class_disconnect_stale_exports(struct obd_device *obd,
+				    int (*test_export)(struct obd_export *))
+{
+	struct list_head work_list;
+	struct obd_export *exp, *n;
+	int evicted = 0;
+
+	INIT_LIST_HEAD(&work_list);
+	spin_lock(&obd->obd_dev_lock);
+	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;
+
+		/* 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);
+
+		list_move(&exp->exp_obd_chain, &work_list);
+		evicted++;
+		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", 0);
+	}
+	spin_unlock(&obd->obd_dev_lock);
+
+	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);
+}
+EXPORT_SYMBOL(class_disconnect_stale_exports);
+
+void class_fail_export(struct obd_export *exp)
+{
+	int rc, already_failed;
+
+	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",
+		       exp, exp->exp_client_uuid.uuid);
+		return;
+	}
+
+	CDEBUG(D_HA, "disconnecting export %p/%s\n",
+	       exp, exp->exp_client_uuid.uuid);
+
+	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. */
+	class_export_get(exp);
+	rc = obd_disconnect(exp);
+	if (rc)
+		CERROR("disconnecting export %p failed: %d\n", exp, rc);
+	else
+		CDEBUG(D_HA, "disconnected export %p/%s\n",
+		       exp, exp->exp_client_uuid.uuid);
+	class_export_put(exp);
+}
+EXPORT_SYMBOL(class_fail_export);
+
+char *obd_export_nid2str(struct obd_export *exp)
+{
+	if (exp->exp_connection != NULL)
+		return libcfs_nid2str(exp->exp_connection->c_peer.nid);
+
+	return "(no nid)";
+}
+EXPORT_SYMBOL(obd_export_nid2str);
+
+int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
+{
+	struct cfs_hash *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;
+
+		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);
+		LASSERTF(doomed_exp != obd->obd_self_export,
+			 "self-export is hashed by NID?\n");
+		exports_evicted++;
+		LCONSOLE_WARN("%s: evicting %s (at %s) by administrative request\n",
+			      obd->obd_name,
+			      obd_uuid2str(&doomed_exp->exp_client_uuid),
+			      obd_export_nid2str(doomed_exp));
+		class_fail_export(doomed_exp);
+		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);
+	return exports_evicted;
+}
+EXPORT_SYMBOL(obd_export_evict_by_nid);
+
+int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
+{
+	struct cfs_hash *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 = cfs_hash_lookup(uuid_hash, &doomed_uuid);
+
+	if (doomed_exp == NULL) {
+		CERROR("%s: can't disconnect %s: no exports found\n",
+		       obd->obd_name, uuid);
+	} else {
+		CWARN("%s: evicting %s at administrative request\n",
+		       obd->obd_name, doomed_exp->exp_client_uuid.uuid);
+		class_fail_export(doomed_exp);
+		class_export_put(doomed_exp);
+		exports_evicted++;
+	}
+	cfs_hash_putref(uuid_hash);
+
+	return exports_evicted;
+}
+EXPORT_SYMBOL(obd_export_evict_by_uuid);
+
+#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;
+
+	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);
+
+	CDEBUG(D_HA, "%s: %s %p %s %s %d (%d %d %d) %d %d %d %d: %p %s %llu\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),
+	       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;
+
+	spin_lock(&obd->obd_dev_lock);
+	list_for_each_entry(exp, &obd->obd_exports, exp_obd_chain)
+		print_export_data(exp, "ACTIVE", locks);
+	list_for_each_entry(exp, &obd->obd_unlinked_exports, exp_obd_chain)
+		print_export_data(exp, "UNLINKED", locks);
+	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);
+	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);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(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, 1);
+		}
+		waited *= 2;
+		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;
+
+/**
+ * kill zombie imports and exports
+ */
+void obd_zombie_impexp_cull(void)
+{
+	struct obd_import *import;
+	struct obd_export *export;
+
+	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);
+		}
+
+		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);
+		}
+
+		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);
+		}
+
+		cond_resched();
+	} while (import != NULL || export != NULL);
+}
+
+static struct completion	obd_zombie_start;
+static struct completion	obd_zombie_stop;
+static unsigned long		obd_zombie_flags;
+static wait_queue_head_t		obd_zombie_waitq;
+static pid_t			obd_zombie_pid;
+
+enum {
+	OBD_ZOMBIE_STOP		= 0x0001,
+};
+
+/**
+ * check for work for kill zombie import/export thread.
+ */
+static int obd_zombie_impexp_check(void *arg)
+{
+	int rc;
+
+	spin_lock(&obd_zombie_impexp_lock);
+	rc = (zombies_count == 0) &&
+	     !test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+	spin_unlock(&obd_zombie_impexp_lock);
+
+	return rc;
+}
+
+/**
+ * Add export to the obd_zombie 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);
+	zombies_count++;
+	list_add(&exp->exp_obd_chain, &obd_zombie_exports);
+	spin_unlock(&obd_zombie_impexp_lock);
+
+	obd_zombie_impexp_notify();
+}
+
+/**
+ * Add import to the obd_zombie thread and notify it.
+ */
+static void obd_zombie_import_add(struct obd_import *imp) {
+	LASSERT(imp->imp_sec == NULL);
+	LASSERT(imp->imp_rq_pool == NULL);
+	spin_lock(&obd_zombie_impexp_lock);
+	LASSERT(list_empty(&imp->imp_zombie_chain));
+	zombies_count++;
+	list_add(&imp->imp_zombie_chain, &obd_zombie_imports);
+	spin_unlock(&obd_zombie_impexp_lock);
+
+	obd_zombie_impexp_notify();
+}
+
+/**
+ * notify import/export destroy thread about new zombie.
+ */
+static void obd_zombie_impexp_notify(void)
+{
+	/*
+	 * Make sure obd_zombie_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
+	 */
+	wake_up_all(&obd_zombie_waitq);
+}
+
+/**
+ * check whether obd_zombie is idle
+ */
+static int obd_zombie_is_idle(void)
+{
+	int 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;
+}
+
+/**
+ * wait when obd_zombie import/export queues become empty
+ */
+void obd_zombie_barrier(void)
+{
+	struct l_wait_info lwi = { 0 };
+
+	if (obd_zombie_pid == current_pid())
+		/* don't wait for myself */
+		return;
+	l_wait_event(obd_zombie_waitq, obd_zombie_is_idle(), &lwi);
+}
+EXPORT_SYMBOL(obd_zombie_barrier);
+
+
+/**
+ * destroy zombie export/import thread.
+ */
+static int obd_zombie_impexp_thread(void *unused)
+{
+	unshare_fs_struct();
+	complete(&obd_zombie_start);
+
+	obd_zombie_pid = current_pid();
+
+	while (!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.
+		 */
+		wake_up(&obd_zombie_waitq);
+	}
+
+	complete(&obd_zombie_stop);
+
+	return 0;
+}
+
+
+/**
+ * start destroy zombie import/export thread
+ */
+int obd_zombie_impexp_init(void)
+{
+	struct task_struct *task;
+
+	INIT_LIST_HEAD(&obd_zombie_imports);
+	INIT_LIST_HEAD(&obd_zombie_exports);
+	spin_lock_init(&obd_zombie_impexp_lock);
+	init_completion(&obd_zombie_start);
+	init_completion(&obd_zombie_stop);
+	init_waitqueue_head(&obd_zombie_waitq);
+	obd_zombie_pid = 0;
+
+	task = kthread_run(obd_zombie_impexp_thread, NULL, "obd_zombid");
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+
+	wait_for_completion(&obd_zombie_start);
+	return 0;
+}
+/**
+ * stop destroy zombie import/export thread
+ */
+void obd_zombie_impexp_stop(void)
+{
+	set_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags);
+	obd_zombie_impexp_notify();
+	wait_for_completion(&obd_zombie_stop);
+}
+
+/***** 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);