LU-8066 obd_type: discard obd_types linked list.

[fs/lustre-release.git] / lustre / obdclass / genops.c

diff --git a/lustre/obdclass/genops.c b/lustre/obdclass/genops.c
index 32a4727..e622041 100644 (file)
--- a/lustre/obdclass/genops.c
+++ b/lustre/obdclass/genops.c
@@ -46,13 +46,11 @@
 #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);
@@ -145,6 +140,11 @@ struct obd_type *class_get_type(const char *name)
                type->typ_refcnt++;
                try_module_get(type->typ_dt_ops->o_owner);
                spin_unlock(&type->obd_type_lock);
+               /* 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);
        }
        return type;
 }
@@ -162,20 +162,12 @@ static void class_sysfs_release(struct kobject *kobj)
 {
        struct obd_type *type = container_of(kobj, struct obd_type, typ_kobj);
 
-#ifdef HAVE_SERVER_SUPPORT
-       if (type->typ_sym_filter)
-               type->typ_debugfs_entry = NULL;
-#endif
        debugfs_remove_recursive(type->typ_debugfs_entry);
        type->typ_debugfs_entry = NULL;
 
        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);
-
 #ifdef CONFIG_PROC_FS
        if (type->typ_name && type->typ_procroot)
                remove_proc_subtree(type->typ_name, proc_lustre_root);
@@ -198,12 +190,11 @@ struct obd_type *class_add_symlinks(const char *name, bool enable_proc)
 {
        struct dentry *symlink;
        struct obd_type *type;
-       struct kobject *kobj;
        int rc;
 
-       kobj = kset_find_obj(lustre_kset, name);
-       if (kobj) {
-               kobject_put(kobj);
+       type = class_search_type(name);
+       if (type) {
+               kobject_put(&type->typ_kobj);
                return ERR_PTR(-EEXIST);
        }
 
@@ -211,8 +202,6 @@ struct obd_type *class_add_symlinks(const char *name, bool enable_proc)
        if (!type)
                return ERR_PTR(-ENOMEM);
 
-       INIT_LIST_HEAD(&type->typ_chain);
-
        type->typ_kobj.kset = lustre_kset;
        rc = kobject_init_and_add(&type->typ_kobj, &class_ktype,
                                  &lustre_kset->kobj, "%s", name);
@@ -256,20 +245,13 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
        /* 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 (strcmp(name, LUSTRE_LOV_NAME) == 0 ||
-                   strcmp(name, LUSTRE_OSC_NAME) == 0) {
-                       struct kobject *kobj;
-
-                       kobj = kset_find_obj(lustre_kset, name);
-                       if (kobj) {
-                               type = container_of(kobj, struct obd_type,
-                                                   typ_kobj);
-                               goto dir_exist;
-                       }
-               }
+               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);
         }
@@ -278,7 +260,6 @@ int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
         if (type == NULL)
                RETURN(-ENOMEM);
 
-       INIT_LIST_HEAD(&type->typ_chain);
        type->typ_kobj.kset = lustre_kset;
        kobject_init(&type->typ_kobj, &class_ktype);
 #ifdef HAVE_SERVER_SUPPORT
@@ -298,8 +279,11 @@ dir_exist:
        spin_lock_init(&type->obd_type_lock);
 
 #ifdef HAVE_SERVER_SUPPORT
-       if (type->typ_sym_filter)
+       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) {
@@ -335,10 +319,6 @@ setup_ldt:
                        GOTO(failed, rc);
        }
 
-       spin_lock(&obd_types_lock);
-       list_add(&type->typ_chain, &obd_types);
-       spin_unlock(&obd_types_lock);
-
        RETURN(0);
 
 failed:
@@ -351,6 +331,7 @@ 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) {
@@ -364,12 +345,16 @@ int class_unregister_type(const char *name)
                 /* Remove ops, but leave the name for debugging */
                 OBD_FREE_PTR(type->typ_dt_ops);
                 OBD_FREE_PTR(type->typ_md_ops);
-                RETURN(-EBUSY);
+               GOTO(out_put, rc = -EBUSY);
         }
 
+       /* Put the final ref */
+       kobject_put(&type->typ_kobj);
+out_put:
+       /* Put the ref returned by class_search_type() */
        kobject_put(&type->typ_kobj);
 
-       RETURN(0);
+       RETURN(rc);
 } /* class_unregister_type */
 EXPORT_SYMBOL(class_unregister_type);
 
@@ -2356,6 +2341,12 @@ __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);