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LU-13503 mdc: allow setting max_mod_rpcs_in_flight larger
[fs/lustre-release.git] / lustre / obdclass / genops.c
index 84a8ce1..d4feb7c 100644 (file)
 #include <lustre_disk.h>
 #include <lustre_kernelcomm.h>
 
-static DEFINE_SPINLOCK(obd_types_lock);
-static LIST_HEAD(obd_types);
 DEFINE_RWLOCK(obd_dev_lock);
 static struct obd_device *obd_devs[MAX_OBD_DEVICES];
 
 static struct kmem_cache *obd_device_cachep;
-
+static struct kobj_type class_ktype;
 static struct workqueue_struct *zombie_wq;
 
 static void obd_zombie_export_add(struct obd_export *exp);
@@ -98,30 +96,26 @@ static void obd_device_free(struct obd_device *obd)
 
 struct obd_type *class_search_type(const char *name)
 {
-       struct list_head *tmp;
-       struct obd_type *type;
+       struct kobject *kobj = kset_find_obj(lustre_kset, name);
 
-       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);
+       if (kobj && kobj->ktype == &class_ktype)
+               return container_of(kobj, struct obd_type, typ_kobj);
+
+       kobject_put(kobj);
        return NULL;
 }
 EXPORT_SYMBOL(class_search_type);
 
 struct obd_type *class_get_type(const char *name)
 {
-        struct obd_type *type = class_search_type(name);
+       struct obd_type *type;
 
+       type = class_search_type(name);
 #ifdef HAVE_MODULE_LOADING_SUPPORT
         if (!type) {
                 const char *modname = name;
 
+#ifdef HAVE_SERVER_SUPPORT
                if (strcmp(modname, "obdfilter") == 0)
                        modname = "ofd";
 
@@ -130,6 +124,7 @@ struct obd_type *class_get_type(const char *name)
 
                if (!strncmp(modname, LUSTRE_MDS_NAME, strlen(LUSTRE_MDS_NAME)))
                        modname = LUSTRE_MDT_NAME;
+#endif /* HAVE_SERVER_SUPPORT */
 
                if (!request_module("%s", modname)) {
                        CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
@@ -141,10 +136,17 @@ struct obd_type *class_get_type(const char *name)
         }
 #endif
         if (type) {
-               spin_lock(&type->obd_type_lock);
-               type->typ_refcnt++;
-               try_module_get(type->typ_dt_ops->o_owner);
-               spin_unlock(&type->obd_type_lock);
+               if (try_module_get(type->typ_dt_ops->o_owner)) {
+                       atomic_inc(&type->typ_refcnt);
+                       /* class_search_type() returned a counted reference,
+                        * but we don't need that count any more as
+                        * we have one through typ_refcnt.
+                        */
+                       kobject_put(&type->typ_kobj);
+               } else {
+                       kobject_put(&type->typ_kobj);
+                       type = NULL;
+               }
        }
        return type;
 }
@@ -152,15 +154,25 @@ 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);
-       type->typ_refcnt--;
        module_put(type->typ_dt_ops->o_owner);
-       spin_unlock(&type->obd_type_lock);
+       atomic_dec(&type->typ_refcnt);
 }
 
 static void class_sysfs_release(struct kobject *kobj)
 {
-       OBD_FREE(kobj, sizeof(*kobj));
+       struct obd_type *type = container_of(kobj, struct obd_type, typ_kobj);
+
+       debugfs_remove_recursive(type->typ_debugfs_entry);
+       type->typ_debugfs_entry = NULL;
+
+       if (type->typ_lu)
+               lu_device_type_fini(type->typ_lu);
+
+#ifdef CONFIG_PROC_FS
+       if (type->typ_name && type->typ_procroot)
+               remove_proc_subtree(type->typ_name, proc_lustre_root);
+#endif
+       OBD_FREE(type, sizeof(*type));
 }
 
 static struct kobj_type class_ktype = {
@@ -168,78 +180,99 @@ static struct kobj_type class_ktype = {
        .release        = class_sysfs_release,
 };
 
-struct kobject *class_setup_tunables(const char *name)
+#ifdef HAVE_SERVER_SUPPORT
+struct obd_type *class_add_symlinks(const char *name, bool enable_proc)
 {
-       struct kobject *kobj;
+       struct dentry *symlink;
+       struct obd_type *type;
        int rc;
 
-#ifdef HAVE_SERVER_SUPPORT
-       kobj = kset_find_obj(lustre_kset, name);
-       if (kobj)
-               return kobj;
-#endif
-       OBD_ALLOC(kobj, sizeof(*kobj));
-       if (!kobj)
+       type = class_search_type(name);
+       if (type) {
+               kobject_put(&type->typ_kobj);
+               return ERR_PTR(-EEXIST);
+       }
+
+       OBD_ALLOC(type, sizeof(*type));
+       if (!type)
                return ERR_PTR(-ENOMEM);
 
-       kobj->kset = lustre_kset;
-       kobject_init(kobj, &class_ktype);
-       rc = kobject_add(kobj, &lustre_kset->kobj, "%s", name);
-       if (rc) {
-               kobject_put(kobj);
+       type->typ_kobj.kset = lustre_kset;
+       rc = kobject_init_and_add(&type->typ_kobj, &class_ktype,
+                                 &lustre_kset->kobj, "%s", name);
+       if (rc)
                return ERR_PTR(rc);
+
+       symlink = debugfs_create_dir(name, debugfs_lustre_root);
+       type->typ_debugfs_entry = symlink;
+       type->typ_sym_filter = true;
+
+       if (enable_proc) {
+               type->typ_procroot = lprocfs_register(name, proc_lustre_root,
+                                                     NULL, NULL);
+               if (IS_ERR(type->typ_procroot)) {
+                       CERROR("%s: can't create compat proc entry: %d\n",
+                              name, (int)PTR_ERR(type->typ_procroot));
+                       type->typ_procroot = NULL;
+               }
        }
-       return kobj;
+
+       return type;
 }
-EXPORT_SYMBOL(class_setup_tunables);
+EXPORT_SYMBOL(class_add_symlinks);
+#endif /* HAVE_SERVER_SUPPORT */
 
 #define CLASS_MAX_NAME 1024
 
-int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
+int class_register_type(const struct obd_ops *dt_ops,
+                       const struct md_ops *md_ops,
                        bool enable_proc, struct lprocfs_vars *vars,
                        const char *name, struct lu_device_type *ldt)
 {
        struct obd_type *type;
-#ifdef HAVE_SERVER_SUPPORT
-       struct qstr dname;
-#endif /* HAVE_SERVER_SUPPORT */
-       int rc = 0;
+       int rc;
 
        ENTRY;
        /* sanity check */
        LASSERT(strnlen(name, CLASS_MAX_NAME) < CLASS_MAX_NAME);
 
-        if (class_search_type(name)) {
+       type = class_search_type(name);
+       if (type) {
+#ifdef HAVE_SERVER_SUPPORT
+               if (type->typ_sym_filter)
+                       goto dir_exist;
+#endif /* HAVE_SERVER_SUPPORT */
+               kobject_put(&type->typ_kobj);
                 CDEBUG(D_IOCTL, "Type %s already registered\n", name);
                 RETURN(-EEXIST);
         }
 
-        rc = -ENOMEM;
         OBD_ALLOC(type, sizeof(*type));
         if (type == NULL)
-                RETURN(rc);
+               RETURN(-ENOMEM);
 
-        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, rc);
+       type->typ_lu = ldt ? OBD_LU_TYPE_SETUP : NULL;
+       type->typ_kobj.kset = lustre_kset;
+       kobject_init(&type->typ_kobj, &class_ktype);
+#ifdef HAVE_SERVER_SUPPORT
+dir_exist:
+#endif /* HAVE_SERVER_SUPPORT */
 
-        *(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_dt_ops = dt_ops;
+       type->typ_md_ops = md_ops;
 
+#ifdef HAVE_SERVER_SUPPORT
+       if (type->typ_sym_filter) {
+               type->typ_sym_filter = false;
+               kobject_put(&type->typ_kobj);
+               goto setup_ldt;
+       }
+#endif
 #ifdef CONFIG_PROC_FS
-       if (enable_proc) {
-               type->typ_procroot = lprocfs_register(type->typ_name,
+       if (enable_proc && !type->typ_procroot) {
+               type->typ_procroot = lprocfs_register(name,
                                                      proc_lustre_root,
-                                                     vars, type);
+                                                     NULL, type);
                if (IS_ERR(type->typ_procroot)) {
                        rc = PTR_ERR(type->typ_procroot);
                        type->typ_procroot = NULL;
@@ -247,76 +280,36 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
                }
        }
 #endif
-#ifdef HAVE_SERVER_SUPPORT
-       dname.name = name;
-       dname.len = strlen(dname.name);
-       dname.hash = ll_full_name_hash(debugfs_lustre_root, dname.name,
-                                      dname.len);
-       type->typ_debugfs_entry = d_lookup(debugfs_lustre_root, &dname);
-       if (type->typ_debugfs_entry) {
-               dput(type->typ_debugfs_entry);
-               type->typ_sym_filter = true;
-               goto dir_exist;
-       }
-#endif /* HAVE_SERVER_SUPPORT */
+       type->typ_debugfs_entry = debugfs_create_dir(name, debugfs_lustre_root);
+       ldebugfs_add_vars(type->typ_debugfs_entry, vars, type);
 
-       type->typ_debugfs_entry = ldebugfs_register(type->typ_name,
-                                                   debugfs_lustre_root,
-                                                   NULL, type);
-       if (IS_ERR_OR_NULL(type->typ_debugfs_entry)) {
-               rc = type->typ_debugfs_entry ? PTR_ERR(type->typ_debugfs_entry)
-                                            : -ENOMEM;
-               type->typ_debugfs_entry = NULL;
+       rc = kobject_add(&type->typ_kobj, &lustre_kset->kobj, "%s", name);
+       if (rc)
                GOTO(failed, rc);
-       }
 #ifdef HAVE_SERVER_SUPPORT
-dir_exist:
+setup_ldt:
 #endif
-       type->typ_kobj = class_setup_tunables(type->typ_name);
-       if (IS_ERR(type->typ_kobj))
-               GOTO(failed, rc = PTR_ERR(type->typ_kobj));
-
        if (ldt) {
-               type->typ_lu = ldt;
                rc = lu_device_type_init(ldt);
-               if (rc) {
-                       kobject_put(type->typ_kobj);
+               smp_store_release(&type->typ_lu, rc ? NULL : ldt);
+               wake_up_var(&type->typ_lu);
+               if (rc)
                        GOTO(failed, rc);
-               }
        }
 
-       spin_lock(&obd_types_lock);
-       list_add(&type->typ_chain, &obd_types);
-       spin_unlock(&obd_types_lock);
-
        RETURN(0);
 
 failed:
-#ifdef HAVE_SERVER_SUPPORT
-       if (type->typ_sym_filter)
-               type->typ_debugfs_entry = NULL;
-#endif
-       if (!IS_ERR_OR_NULL(type->typ_debugfs_entry))
-               ldebugfs_remove(&type->typ_debugfs_entry);
-       if (type->typ_name != NULL) {
-#ifdef CONFIG_PROC_FS
-               if (type->typ_procroot != NULL)
-                       remove_proc_subtree(type->typ_name, proc_lustre_root);
-#endif
-                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);
+       kobject_put(&type->typ_kobj);
+
+       RETURN(rc);
 }
 EXPORT_SYMBOL(class_register_type);
 
 int class_unregister_type(const char *name)
 {
         struct obd_type *type = class_search_type(name);
+       int rc = 0;
         ENTRY;
 
         if (!type) {
@@ -324,47 +317,23 @@ int class_unregister_type(const char *name)
                 RETURN(-EINVAL);
         }
 
-        if (type->typ_refcnt) {
-                CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt);
+       if (atomic_read(&type->typ_refcnt)) {
+               CERROR("type %s has refcount (%d)\n", name,
+                      atomic_read(&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);
+               type->typ_dt_ops = NULL;
+               type->typ_md_ops = NULL;
+               GOTO(out_put, rc = -EBUSY);
         }
 
-       kobject_put(type->typ_kobj);
+       /* Put the final ref */
+       kobject_put(&type->typ_kobj);
+out_put:
+       /* Put the ref returned by class_search_type() */
+       kobject_put(&type->typ_kobj);
 
-       /* we do not use type->typ_procroot as for compatibility purposes
-        * other modules can share names (i.e. lod can use lov entry). so
-        * we can't reference pointer as it can get invalided when another
-        * module removes the entry */
-#ifdef CONFIG_PROC_FS
-       if (type->typ_procroot != NULL)
-               remove_proc_subtree(type->typ_name, proc_lustre_root);
-       if (type->typ_procsym != NULL)
-               lprocfs_remove(&type->typ_procsym);
-#endif
-#ifdef HAVE_SERVER_SUPPORT
-       if (type->typ_sym_filter)
-               type->typ_debugfs_entry = NULL;
-#endif
-       if (!IS_ERR_OR_NULL(type->typ_debugfs_entry))
-               ldebugfs_remove(&type->typ_debugfs_entry);
-
-        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);
+       RETURN(rc);
 } /* class_unregister_type */
 EXPORT_SYMBOL(class_unregister_type);
 
@@ -445,7 +414,7 @@ struct obd_device *class_newdev(const char *type_name, const char *name,
 
        newdev->obd_conn_inprogress = 0;
 
-       strncpy(newdev->obd_uuid.uuid, uuid, strlen(uuid));
+       strncpy(newdev->obd_uuid.uuid, uuid, UUID_MAX);
 
        CDEBUG(D_IOCTL, "Allocate new device %s (%p)\n",
               newdev->obd_name, newdev);
@@ -696,6 +665,7 @@ struct obd_device *class_num2obd(int num)
 
         return obd;
 }
+EXPORT_SYMBOL(class_num2obd);
 
 /**
  * Find obd in obd_dev[] by name or uuid.
@@ -777,15 +747,15 @@ void class_obd_list(void)
                         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)
+ * 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 *type_name,
+                                        struct obd_uuid *grp_uuid)
 {
         int i;
 
@@ -795,8 +765,8 @@ struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 
                 if (obd == NULL)
                         continue;
-                if ((strncmp(obd->obd_type->typ_name, typ_name,
-                             strlen(typ_name)) == 0)) {
+               if ((strncmp(obd->obd_type->typ_name, type_name,
+                            strlen(type_name)) == 0)) {
                         if (obd_uuid_equals(tgt_uuid,
                                             &obd->u.cli.cl_target_uuid) &&
                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
@@ -813,10 +783,11 @@ struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 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)
+ * 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;
 
@@ -910,9 +881,9 @@ int obd_init_caches(void)
        ENTRY;
 
        LASSERT(obd_device_cachep == NULL);
-       obd_device_cachep = kmem_cache_create("ll_obd_dev_cache",
-                                             sizeof(struct obd_device),
-                                             0, 0, NULL);
+       obd_device_cachep = kmem_cache_create_usercopy("ll_obd_dev_cache",
+                               sizeof(struct obd_device),
+                               0, 0, 0, sizeof(struct obd_device), NULL);
        if (!obd_device_cachep)
                GOTO(out, rc = -ENOMEM);
 
@@ -922,6 +893,8 @@ out:
        RETURN(rc);
 }
 
+static const char export_handle_owner[] = "export";
+
 /* map connection to client */
 struct obd_export *class_conn2export(struct lustre_handle *conn)
 {
@@ -939,7 +912,7 @@ struct obd_export *class_conn2export(struct lustre_handle *conn)
         }
 
        CDEBUG(D_INFO, "looking for export cookie %#llx\n", conn->cookie);
-       export = class_handle2object(conn->cookie, NULL);
+       export = class_handle2object(conn->cookie, export_handle_owner);
        RETURN(export);
 }
 EXPORT_SYMBOL(class_conn2export);
@@ -952,18 +925,6 @@ struct obd_device *class_exp2obd(struct obd_export *exp)
 }
 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;
-}
-
 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 {
         struct obd_device *obd = exp->exp_obd;
@@ -973,21 +934,13 @@ struct obd_import *class_exp2cliimp(struct obd_export *exp)
 }
 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 management functions */
 static void class_export_destroy(struct obd_export *exp)
 {
         struct obd_device *obd = exp->exp_obd;
         ENTRY;
 
-        LASSERT_ATOMIC_ZERO(&exp->exp_refcount);
+       LASSERT(refcount_read(&exp->exp_handle.h_ref) == 0);
        LASSERT(obd != NULL);
 
         CDEBUG(D_IOCTL, "destroying export %p/%s for %s\n", exp,
@@ -1007,25 +960,16 @@ static void class_export_destroy(struct obd_export *exp)
        if (exp != obd->obd_self_export)
                class_decref(obd, "export", exp);
 
-        OBD_FREE_RCU(exp, sizeof(*exp), &exp->exp_handle);
+       OBD_FREE_PRE(exp, sizeof(*exp), "rcu");
+       kfree_rcu(exp, exp_handle.h_rcu);
         EXIT;
 }
 
-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));
+       refcount_inc(&exp->exp_handle.h_ref);
+       CDEBUG(D_INFO, "GET export %p refcount=%d\n", exp,
+              refcount_read(&exp->exp_handle.h_ref));
         return exp;
 }
 EXPORT_SYMBOL(class_export_get);
@@ -1033,11 +977,12 @@ 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);
+       LASSERT(refcount_read(&exp->exp_handle.h_ref) >  0);
+       LASSERT(refcount_read(&exp->exp_handle.h_ref) < LI_POISON);
         CDEBUG(D_INFO, "PUTting export %p : new refcount %d\n", exp,
-              atomic_read(&exp->exp_refcount) - 1);
+              refcount_read(&exp->exp_handle.h_ref) - 1);
 
-       if (atomic_dec_and_test(&exp->exp_refcount)) {
+       if (refcount_dec_and_test(&exp->exp_handle.h_ref)) {
                struct obd_device *obd = exp->exp_obd;
 
                CDEBUG(D_IOCTL, "final put %p/%s\n",
@@ -1080,7 +1025,6 @@ struct obd_export *__class_new_export(struct obd_device *obd,
                                      struct obd_uuid *cluuid, bool is_self)
 {
         struct obd_export *export;
-       struct cfs_hash *hash = NULL;
         int rc = 0;
         ENTRY;
 
@@ -1092,7 +1036,7 @@ struct obd_export *__class_new_export(struct obd_device *obd,
         export->exp_lock_hash = NULL;
        export->exp_flock_hash = NULL;
        /* 2 = class_handle_hash + last */
-       atomic_set(&export->exp_refcount, 2);
+       refcount_set(&export->exp_handle.h_ref, 2);
        atomic_set(&export->exp_rpc_count, 0);
        atomic_set(&export->exp_cb_count, 0);
        atomic_set(&export->exp_locks_count, 0);
@@ -1106,14 +1050,13 @@ struct obd_export *__class_new_export(struct obd_device *obd,
        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_RCU(&export->exp_handle.h_link);
+       INIT_HLIST_NODE(&export->exp_handle.h_link);
        INIT_LIST_HEAD(&export->exp_hp_rpcs);
        INIT_LIST_HEAD(&export->exp_reg_rpcs);
-       class_handle_hash(&export->exp_handle, &export_handle_ops);
+       class_handle_hash(&export->exp_handle, export_handle_owner);
        export->exp_last_request_time = ktime_get_real_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);
        INIT_HLIST_NODE(&export->exp_gen_hash);
        spin_lock_init(&export->exp_bl_list_lock);
@@ -1126,33 +1069,22 @@ struct obd_export *__class_new_export(struct obd_device *obd,
        export->exp_client_uuid = *cluuid;
        obd_init_export(export);
 
+       at_init(&export->exp_bl_lock_at, obd_timeout, 0);
+
+       spin_lock(&obd->obd_dev_lock);
        if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
-               spin_lock(&obd->obd_dev_lock);
                /* shouldn't happen, but might race */
                if (obd->obd_stopping)
                        GOTO(exit_unlock, rc = -ENODEV);
 
-               hash = cfs_hash_getref(obd->obd_uuid_hash);
-               if (hash == NULL)
-                       GOTO(exit_unlock, rc = -ENODEV);
-               spin_unlock(&obd->obd_dev_lock);
-
-                rc = cfs_hash_add_unique(hash, cluuid, &export->exp_uuid_hash);
+               rc = obd_uuid_add(obd, export);
                 if (rc != 0) {
-                        LCONSOLE_WARN("%s: denying duplicate export for %s, %d\n",
+                       LCONSOLE_WARN("%s: denying duplicate export for %s: rc = %d\n",
                                       obd->obd_name, cluuid->uuid, rc);
-                        GOTO(exit_err, rc = -EALREADY);
+                       GOTO(exit_unlock, rc = -EALREADY);
                 }
         }
 
-       at_init(&export->exp_bl_lock_at, obd_timeout, 0);
-       spin_lock(&obd->obd_dev_lock);
-        if (obd->obd_stopping) {
-               if (hash)
-                       cfs_hash_del(hash, cluuid, &export->exp_uuid_hash);
-               GOTO(exit_unlock, rc = -ESHUTDOWN);
-        }
-
        if (!is_self) {
                class_incref(obd, "export", export);
                list_add_tail(&export->exp_obd_chain_timed,
@@ -1164,17 +1096,11 @@ struct obd_export *__class_new_export(struct obd_device *obd,
                INIT_LIST_HEAD(&export->exp_obd_chain);
        }
        spin_unlock(&obd->obd_dev_lock);
-       if (hash)
-               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);
@@ -1204,10 +1130,8 @@ void class_unlink_export(struct obd_export *exp)
 
        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);
+       if (exp != exp->exp_obd->obd_self_export)
+               obd_uuid_del(exp->exp_obd, exp);
 
 #ifdef HAVE_SERVER_SUPPORT
        if (!hlist_unhashed(&exp->exp_gen_hash)) {
@@ -1236,48 +1160,40 @@ void class_unlink_export(struct obd_export *exp)
 EXPORT_SYMBOL(class_unlink_export);
 
 /* Import management functions */
-static void class_import_destroy(struct obd_import *imp)
+static void obd_zombie_import_free(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);
+       LASSERT(refcount_read(&imp->imp_refcount) == 0);
 
         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);
+               imp_conn = list_first_entry(&imp->imp_conn_list,
+                                           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);
+       LASSERTF(atomic_read(&imp->imp_reqs) == 0, "%s: imp_reqs = %d\n",
+                imp->imp_obd->obd_name, atomic_read(&imp->imp_reqs));
         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);
+       OBD_FREE_PTR(imp);
+       EXIT;
 }
 
-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);
+       refcount_inc(&import->imp_refcount);
         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", import,
-              atomic_read(&import->imp_refcount),
+              refcount_read(&import->imp_refcount),
                import->imp_obd->obd_name);
         return import;
 }
@@ -1287,19 +1203,17 @@ void class_import_put(struct obd_import *imp)
 {
        ENTRY;
 
-        LASSERT_ATOMIC_GT_LT(&imp->imp_refcount, 0, LI_POISON);
+       LASSERT(refcount_read(&imp->imp_refcount) > 0);
 
         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", imp,
-              atomic_read(&imp->imp_refcount) - 1,
+              refcount_read(&imp->imp_refcount) - 1,
                imp->imp_obd->obd_name);
 
-       if (atomic_dec_and_test(&imp->imp_refcount)) {
+       if (refcount_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);
        EXIT;
 }
 EXPORT_SYMBOL(class_import_put);
@@ -1321,7 +1235,7 @@ static void obd_zombie_imp_cull(struct work_struct *ws)
        struct obd_import *import;
 
        import = container_of(ws, struct obd_import, imp_zombie_work);
-       class_import_destroy(import);
+       obd_zombie_import_free(import);
 }
 
 struct obd_import *class_new_import(struct obd_device *obd)
@@ -1345,23 +1259,22 @@ struct obd_import *class_new_import(struct obd_device *obd)
        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);
+       rwlock_init(&imp->imp_sec_lock);
        init_waitqueue_head(&imp->imp_recovery_waitq);
        INIT_WORK(&imp->imp_zombie_work, obd_zombie_imp_cull);
 
-       if (curr_pid_ns->child_reaper)
+       if (curr_pid_ns && curr_pid_ns->child_reaper)
                imp->imp_sec_refpid = curr_pid_ns->child_reaper->pid;
        else
                imp->imp_sec_refpid = 1;
 
-       atomic_set(&imp->imp_refcount, 2);
+       refcount_set(&imp->imp_refcount, 2);
        atomic_set(&imp->imp_unregistering, 0);
+       atomic_set(&imp->imp_reqs, 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_RCU(&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
@@ -1377,8 +1290,6 @@ 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);
@@ -1568,8 +1479,8 @@ static void class_disconnect_export_list(struct list_head *list,
         /* It's possible that an export may disconnect itself, but
          * nothing else will be added to this list. */
        while (!list_empty(list)) {
-               exp = list_entry(list->next, struct obd_export,
-                                exp_obd_chain);
+               exp = list_first_entry(list, struct obd_export,
+                                      exp_obd_chain);
                /* need for safe call CDEBUG after obd_disconnect */
                class_export_get(exp);
 
@@ -1606,11 +1517,10 @@ static void class_disconnect_export_list(struct list_head *list,
 
 void class_disconnect_exports(struct obd_device *obd)
 {
-       struct list_head work_list;
+       LIST_HEAD(work_list);
        ENTRY;
 
        /* 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);
@@ -1633,12 +1543,11 @@ EXPORT_SYMBOL(class_disconnect_exports);
 void class_disconnect_stale_exports(struct obd_device *obd,
                                     int (*test_export)(struct obd_export *))
 {
-       struct list_head work_list;
+       LIST_HEAD(work_list);
        struct obd_export *exp, *n;
-        int evicted = 0;
-        ENTRY;
+       int evicted = 0;
+       ENTRY;
 
-       INIT_LIST_HEAD(&work_list);
        spin_lock(&obd->obd_dev_lock);
        list_for_each_entry_safe(exp, n, &obd->obd_exports,
                                 exp_obd_chain) {
@@ -1765,9 +1674,9 @@ int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
 }
 EXPORT_SYMBOL(obd_export_evict_by_nid);
 
+#ifdef HAVE_SERVER_SUPPORT
 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;
@@ -1777,19 +1686,15 @@ int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
                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);
-
+       doomed_exp = obd_uuid_lookup(obd, &doomed_uuid);
         if (doomed_exp == NULL) {
                 CERROR("%s: can't disconnect %s: no exports found\n",
                        obd->obd_name, uuid);
@@ -1798,12 +1703,13 @@ int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
                        obd->obd_name, doomed_exp->exp_client_uuid.uuid);
                 class_fail_export(doomed_exp);
                 class_export_put(doomed_exp);
+               obd_uuid_del(obd, doomed_exp);
                 exports_evicted++;
         }
-       cfs_hash_putref(uuid_hash);
 
         return exports_evicted;
 }
+#endif /* HAVE_SERVER_SUPPORT */
 
 #if LUSTRE_TRACKS_LOCK_EXP_REFS
 void (*class_export_dump_hook)(struct obd_export*) = NULL;
@@ -1829,7 +1735,8 @@ static void print_export_data(struct obd_export *exp, const char *status,
        CDEBUG(debug_level, "%s: %s %p %s %s %d (%d %d %d) %d %d %d %d: "
               "%p %s %llu stale:%d\n",
               exp->exp_obd->obd_name, status, exp, exp->exp_client_uuid.uuid,
-              obd_export_nid2str(exp), atomic_read(&exp->exp_refcount),
+              obd_export_nid2str(exp),
+              refcount_read(&exp->exp_handle.h_ref),
               atomic_read(&exp->exp_rpc_count),
               atomic_read(&exp->exp_cb_count),
               atomic_read(&exp->exp_locks_count),
@@ -1863,8 +1770,7 @@ void obd_exports_barrier(struct obd_device *obd)
        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));
+               schedule_timeout_uninterruptible(cfs_time_seconds(waited));
                if (waited > 5 && is_power_of_2(waited)) {
                        LCONSOLE_WARN("%s is waiting for obd_unlinked_exports "
                                      "more than %d seconds. "
@@ -1919,8 +1825,8 @@ struct obd_export *obd_stale_export_get(void)
 
        spin_lock(&obd_stale_export_lock);
        if (!list_empty(&obd_stale_exports)) {
-               exp = list_entry(obd_stale_exports.next,
-                                struct obd_export, exp_stale_list);
+               exp = list_first_entry(&obd_stale_exports,
+                                      struct obd_export, exp_stale_list);
                list_del_init(&exp->exp_stale_list);
        }
        spin_unlock(&obd_stale_export_lock);
@@ -1987,11 +1893,11 @@ EXPORT_SYMBOL(obd_stale_export_adjust);
  */
 int obd_zombie_impexp_init(void)
 {
-       zombie_wq = alloc_workqueue("obd_zombid", 0, 0);
-       if (!zombie_wq)
-               return -ENOMEM;
+       zombie_wq = cfs_cpt_bind_workqueue("obd_zombid", cfs_cpt_tab,
+                                          0, CFS_CPT_ANY,
+                                          cfs_cpt_number(cfs_cpt_tab));
 
-       return 0;
+       return IS_ERR(zombie_wq) ? PTR_ERR(zombie_wq) : 0;
 }
 
 /**
@@ -2081,7 +1987,6 @@ static bool obd_request_slot_avail(struct client_obd *cli,
 int obd_get_request_slot(struct client_obd *cli)
 {
        struct obd_request_slot_waiter   orsw;
-       struct l_wait_info               lwi;
        int                              rc;
 
        spin_lock(&cli->cl_loi_list_lock);
@@ -2096,11 +2001,9 @@ int obd_get_request_slot(struct client_obd *cli)
        orsw.orsw_signaled = false;
        spin_unlock(&cli->cl_loi_list_lock);
 
-       lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
-       rc = l_wait_event(orsw.orsw_waitq,
-                         obd_request_slot_avail(cli, &orsw) ||
-                         orsw.orsw_signaled,
-                         &lwi);
+       rc = l_wait_event_abortable(orsw.orsw_waitq,
+                                   obd_request_slot_avail(cli, &orsw) ||
+                                   orsw.orsw_signaled);
 
        /* Here, we must take the lock to avoid the on-stack 'orsw' to be
         * freed but other (such as obd_put_request_slot) is using it. */
@@ -2112,6 +2015,7 @@ int obd_get_request_slot(struct client_obd *cli)
                        else
                                list_del(&orsw.orsw_entry);
                }
+               rc = -EINTR;
        }
 
        if (orsw.orsw_signaled) {
@@ -2135,8 +2039,9 @@ void obd_put_request_slot(struct client_obd *cli)
        /* If there is free slot, wakeup the first waiter. */
        if (!list_empty(&cli->cl_flight_waiters) &&
            likely(cli->cl_rpcs_in_flight < cli->cl_max_rpcs_in_flight)) {
-               orsw = list_entry(cli->cl_flight_waiters.next,
-                                 struct obd_request_slot_waiter, orsw_entry);
+               orsw = list_first_entry(&cli->cl_flight_waiters,
+                                       struct obd_request_slot_waiter,
+                                       orsw_entry);
                list_del_init(&orsw->orsw_entry);
                cli->cl_rpcs_in_flight++;
                wake_up(&orsw->orsw_waitq);
@@ -2157,20 +2062,21 @@ int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
        __u32                           old;
        int                             diff;
        int                             i;
-       char                            *typ_name;
        int                             rc;
 
        if (max > OBD_MAX_RIF_MAX || max < 1)
                return -ERANGE;
 
-       typ_name = cli->cl_import->imp_obd->obd_type->typ_name;
-       if (strcmp(typ_name, LUSTRE_MDC_NAME) == 0) {
+       CDEBUG(D_INFO, "%s: max = %hu max_mod = %u rif = %u\n",
+              cli->cl_import->imp_obd->obd_name, max,
+              cli->cl_max_mod_rpcs_in_flight, cli->cl_max_rpcs_in_flight);
+
+       if (strcmp(cli->cl_import->imp_obd->obd_type->typ_name,
+                  LUSTRE_MDC_NAME) == 0) {
                /* adjust max_mod_rpcs_in_flight to ensure it is always
                 * strictly lower that max_rpcs_in_flight */
                if (max < 2) {
-                       CERROR("%s: cannot set max_rpcs_in_flight to 1 "
-                              "because it must be higher than "
-                              "max_mod_rpcs_in_flight value",
+                       CERROR("%s: cannot set mdc.*.max_rpcs_in_flight=1\n",
                               cli->cl_import->imp_obd->obd_name);
                        return -ERANGE;
                }
@@ -2193,8 +2099,9 @@ int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
                if (list_empty(&cli->cl_flight_waiters))
                        break;
 
-               orsw = list_entry(cli->cl_flight_waiters.next,
-                                 struct obd_request_slot_waiter, orsw_entry);
+               orsw = list_first_entry(&cli->cl_flight_waiters,
+                                       struct obd_request_slot_waiter,
+                                       orsw_entry);
                list_del_init(&orsw->orsw_entry);
                cli->cl_rpcs_in_flight++;
                wake_up(&orsw->orsw_waitq);
@@ -2213,32 +2120,50 @@ EXPORT_SYMBOL(obd_get_max_mod_rpcs_in_flight);
 
 int obd_set_max_mod_rpcs_in_flight(struct client_obd *cli, __u16 max)
 {
-       struct obd_connect_data *ocd;
+       struct obd_connect_data *ocd;
        __u16 maxmodrpcs;
        __u16 prev;
 
        if (max > OBD_MAX_RIF_MAX || max < 1)
                return -ERANGE;
 
-       /* cannot exceed or equal max_rpcs_in_flight */
+       ocd = &cli->cl_import->imp_connect_data;
+       CDEBUG(D_INFO, "%s: max = %hu flags = %llx, max_mod = %u rif = %u\n",
+              cli->cl_import->imp_obd->obd_name, max, ocd->ocd_connect_flags,
+              ocd->ocd_maxmodrpcs, cli->cl_max_rpcs_in_flight);
+
+       if (max == OBD_MAX_RIF_MAX)
+               max = OBD_MAX_RIF_MAX - 1;
+
+       /* Cannot exceed or equal max_rpcs_in_flight.  If we are asked to
+        * increase this value, also bump up max_rpcs_in_flight to match.
+        */
        if (max >= cli->cl_max_rpcs_in_flight) {
-               CERROR("%s: can't set max_mod_rpcs_in_flight to a value (%hu) "
-                      "higher or equal to max_rpcs_in_flight value (%u)\n",
-                      cli->cl_import->imp_obd->obd_name,
-                      max, cli->cl_max_rpcs_in_flight);
-               return -ERANGE;
+               CDEBUG(D_INFO,
+                      "%s: increasing max_rpcs_in_flight=%hu to allow larger max_mod_rpcs_in_flight=%u\n",
+                      cli->cl_import->imp_obd->obd_name, max + 1, max);
+               obd_set_max_rpcs_in_flight(cli, max + 1);
        }
 
-       /* cannot exceed max modify RPCs in flight supported by the server */
-       ocd = &cli->cl_import->imp_connect_data;
-       if (ocd->ocd_connect_flags & OBD_CONNECT_MULTIMODRPCS)
+       /* cannot exceed max modify RPCs in flight supported by the server,
+        * but verify ocd_connect_flags is at least initialized first.  If
+        * not, allow it and fix value later in ptlrpc_connect_set_flags().
+        */
+       if (!ocd->ocd_connect_flags) {
+               maxmodrpcs = cli->cl_max_rpcs_in_flight - 1;
+       } else if (ocd->ocd_connect_flags & OBD_CONNECT_MULTIMODRPCS) {
                maxmodrpcs = ocd->ocd_maxmodrpcs;
-       else
+               if (maxmodrpcs == 0) { /* connection not finished yet */
+                       maxmodrpcs = cli->cl_max_rpcs_in_flight - 1;
+                       CDEBUG(D_INFO,
+                              "%s: partial connect, assume maxmodrpcs=%hu\n",
+                              cli->cl_import->imp_obd->obd_name, maxmodrpcs);
+               }
+       } else {
                maxmodrpcs = 1;
+       }
        if (max > maxmodrpcs) {
-               CERROR("%s: can't set max_mod_rpcs_in_flight to a value (%hu) "
-                      "higher than max_mod_rpcs_per_client value (%hu) "
-                      "returned by the server at connection\n",
+               CERROR("%s: can't set max_mod_rpcs_in_flight=%hu higher than ocd_maxmodrpcs=%hu returned by the server at connection\n",
                       cli->cl_import->imp_obd->obd_name,
                       max, maxmodrpcs);
                return -ERANGE;
@@ -2259,8 +2184,6 @@ int obd_set_max_mod_rpcs_in_flight(struct client_obd *cli, __u16 max)
 }
 EXPORT_SYMBOL(obd_set_max_mod_rpcs_in_flight);
 
-
-#define pct(a, b) (b ? a * 100 / b : 0)
 int obd_mod_rpc_stats_seq_show(struct client_obd *cli,
                               struct seq_file *seq)
 {
@@ -2286,7 +2209,7 @@ int obd_mod_rpc_stats_seq_show(struct client_obd *cli,
        for (i = 0; i < OBD_HIST_MAX; i++) {
                unsigned long mod = cli->cl_mod_rpcs_hist.oh_buckets[i];
                mod_cum += mod;
-               seq_printf(seq, "%d:\t\t%10lu %3lu %3lu\n",
+               seq_printf(seq, "%d:\t\t%10lu %3u %3u\n",
                           i, mod, pct(mod, mod_tot),
                           pct(mod_cum, mod_tot));
                if (mod_cum == mod_tot)
@@ -2298,8 +2221,6 @@ int obd_mod_rpc_stats_seq_show(struct client_obd *cli,
        return 0;
 }
 EXPORT_SYMBOL(obd_mod_rpc_stats_seq_show);
-#undef pct
-
 
 /* The number of modify RPCs sent in parallel is limited
  * because the server has a finite number of slots per client to
@@ -2336,15 +2257,6 @@ static inline bool obd_mod_rpc_slot_avail(struct client_obd *cli,
        return avail;
 }
 
-static inline bool obd_skip_mod_rpc_slot(const struct lookup_intent *it)
-{
-       if (it != NULL &&
-           (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
-            it->it_op == IT_READDIR ||
-            (it->it_op == IT_LAYOUT && !(it->it_flags & MDS_FMODE_WRITE))))
-                       return true;
-       return false;
-}
 
 /* Get a modify RPC slot from the obd client @cli according
  * to the kind of operation @opc that is going to be sent
@@ -2354,19 +2266,11 @@ static inline bool obd_skip_mod_rpc_slot(const struct lookup_intent *it)
  * Returns the tag to be set in the request message. Tag 0
  * is reserved for non-modifying requests.
  */
-__u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc,
-                          struct lookup_intent *it)
+__u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc)
 {
-       struct l_wait_info      lwi = LWI_INTR(NULL, NULL);
        bool                    close_req = false;
        __u16                   i, max;
 
-       /* read-only metadata RPCs don't consume a slot on MDT
-        * for reply reconstruction
-        */
-       if (obd_skip_mod_rpc_slot(it))
-               return 0;
-
        if (opc == MDS_CLOSE)
                close_req = true;
 
@@ -2387,6 +2291,12 @@ __u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc,
                        LASSERT(!test_and_set_bit(i, cli->cl_mod_tag_bitmap));
                        spin_unlock(&cli->cl_mod_rpcs_lock);
                        /* tag 0 is reserved for non-modify RPCs */
+
+                       CDEBUG(D_RPCTRACE,
+                              "%s: modify RPC slot %u is allocated opc %u, max %hu\n",
+                              cli->cl_import->imp_obd->obd_name,
+                              i + 1, opc, max);
+
                        return i + 1;
                }
                spin_unlock(&cli->cl_mod_rpcs_lock);
@@ -2395,23 +2305,21 @@ __u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc,
                       "opc %u, max %hu\n",
                       cli->cl_import->imp_obd->obd_name, opc, max);
 
-               l_wait_event_exclusive(cli->cl_mod_rpcs_waitq,
-                                      obd_mod_rpc_slot_avail(cli, close_req),
-                                      &lwi);
+               wait_event_idle_exclusive(cli->cl_mod_rpcs_waitq,
+                                         obd_mod_rpc_slot_avail(cli,
+                                                                close_req));
        } while (true);
 }
 EXPORT_SYMBOL(obd_get_mod_rpc_slot);
 
 /* Put a modify RPC slot from the obd client @cli according
- * to the kind of operation @opc that has been sent and the
- * intent @it of the operation if it applies.
+ * to the kind of operation @opc that has been sent.
  */
-void obd_put_mod_rpc_slot(struct client_obd *cli, __u32 opc,
-                         struct lookup_intent *it, __u16 tag)
+void obd_put_mod_rpc_slot(struct client_obd *cli, __u32 opc, __u16 tag)
 {
        bool                    close_req = false;
 
-       if (obd_skip_mod_rpc_slot(it))
+       if (tag == 0)
                return;
 
        if (opc == MDS_CLOSE)