v4.19.13 snapshot.
diff --git a/include/linux/configfs.h b/include/linux/configfs.h
new file mode 100644
index 0000000..90b90f8
--- /dev/null
+++ b/include/linux/configfs.h
@@ -0,0 +1,289 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * configfs.h - definitions for the device driver filesystem
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * Based on kobject.h:
+ * Copyright (c) 2002-2003 Patrick Mochel
+ * Copyright (c) 2002-2003 Open Source Development Labs
+ *
+ * configfs Copyright (C) 2005 Oracle. All rights reserved.
+ *
+ * Please read Documentation/filesystems/configfs/configfs.txt before using
+ * the configfs interface, ESPECIALLY the parts about reference counts and
+ * item destructors.
+ */
+
+#ifndef _CONFIGFS_H_
+#define _CONFIGFS_H_
+
+#include <linux/stat.h> /* S_IRUGO */
+#include <linux/types.h> /* ssize_t */
+#include <linux/list.h> /* struct list_head */
+#include <linux/kref.h> /* struct kref */
+#include <linux/mutex.h> /* struct mutex */
+
+#define CONFIGFS_ITEM_NAME_LEN 20
+
+struct module;
+
+struct configfs_item_operations;
+struct configfs_group_operations;
+struct configfs_attribute;
+struct configfs_bin_attribute;
+struct configfs_subsystem;
+
+struct config_item {
+ char *ci_name;
+ char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
+ struct kref ci_kref;
+ struct list_head ci_entry;
+ struct config_item *ci_parent;
+ struct config_group *ci_group;
+ const struct config_item_type *ci_type;
+ struct dentry *ci_dentry;
+};
+
+extern __printf(2, 3)
+int config_item_set_name(struct config_item *, const char *, ...);
+
+static inline char *config_item_name(struct config_item * item)
+{
+ return item->ci_name;
+}
+
+extern void config_item_init_type_name(struct config_item *item,
+ const char *name,
+ const struct config_item_type *type);
+
+extern struct config_item *config_item_get(struct config_item *);
+extern struct config_item *config_item_get_unless_zero(struct config_item *);
+extern void config_item_put(struct config_item *);
+
+struct config_item_type {
+ struct module *ct_owner;
+ struct configfs_item_operations *ct_item_ops;
+ struct configfs_group_operations *ct_group_ops;
+ struct configfs_attribute **ct_attrs;
+ struct configfs_bin_attribute **ct_bin_attrs;
+};
+
+/**
+ * group - a group of config_items of a specific type, belonging
+ * to a specific subsystem.
+ */
+struct config_group {
+ struct config_item cg_item;
+ struct list_head cg_children;
+ struct configfs_subsystem *cg_subsys;
+ struct list_head default_groups;
+ struct list_head group_entry;
+};
+
+extern void config_group_init(struct config_group *group);
+extern void config_group_init_type_name(struct config_group *group,
+ const char *name,
+ const struct config_item_type *type);
+
+static inline struct config_group *to_config_group(struct config_item *item)
+{
+ return item ? container_of(item,struct config_group,cg_item) : NULL;
+}
+
+static inline struct config_group *config_group_get(struct config_group *group)
+{
+ return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
+}
+
+static inline void config_group_put(struct config_group *group)
+{
+ config_item_put(&group->cg_item);
+}
+
+extern struct config_item *config_group_find_item(struct config_group *,
+ const char *);
+
+
+static inline void configfs_add_default_group(struct config_group *new_group,
+ struct config_group *group)
+{
+ list_add_tail(&new_group->group_entry, &group->default_groups);
+}
+
+struct configfs_attribute {
+ const char *ca_name;
+ struct module *ca_owner;
+ umode_t ca_mode;
+ ssize_t (*show)(struct config_item *, char *);
+ ssize_t (*store)(struct config_item *, const char *, size_t);
+};
+
+#define CONFIGFS_ATTR(_pfx, _name) \
+static struct configfs_attribute _pfx##attr_##_name = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IRUGO | S_IWUSR, \
+ .ca_owner = THIS_MODULE, \
+ .show = _pfx##_name##_show, \
+ .store = _pfx##_name##_store, \
+}
+
+#define CONFIGFS_ATTR_RO(_pfx, _name) \
+static struct configfs_attribute _pfx##attr_##_name = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IRUGO, \
+ .ca_owner = THIS_MODULE, \
+ .show = _pfx##_name##_show, \
+}
+
+#define CONFIGFS_ATTR_WO(_pfx, _name) \
+static struct configfs_attribute _pfx##attr_##_name = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IWUSR, \
+ .ca_owner = THIS_MODULE, \
+ .store = _pfx##_name##_store, \
+}
+
+struct file;
+struct vm_area_struct;
+
+struct configfs_bin_attribute {
+ struct configfs_attribute cb_attr; /* std. attribute */
+ void *cb_private; /* for user */
+ size_t cb_max_size; /* max core size */
+ ssize_t (*read)(struct config_item *, void *, size_t);
+ ssize_t (*write)(struct config_item *, const void *, size_t);
+};
+
+#define CONFIGFS_BIN_ATTR(_pfx, _name, _priv, _maxsz) \
+static struct configfs_bin_attribute _pfx##attr_##_name = { \
+ .cb_attr = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IRUGO | S_IWUSR, \
+ .ca_owner = THIS_MODULE, \
+ }, \
+ .cb_private = _priv, \
+ .cb_max_size = _maxsz, \
+ .read = _pfx##_name##_read, \
+ .write = _pfx##_name##_write, \
+}
+
+#define CONFIGFS_BIN_ATTR_RO(_pfx, _name, _priv, _maxsz) \
+static struct configfs_bin_attribute _pfx##attr_##_name = { \
+ .cb_attr = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IRUGO, \
+ .ca_owner = THIS_MODULE, \
+ }, \
+ .cb_private = _priv, \
+ .cb_max_size = _maxsz, \
+ .read = _pfx##_name##_read, \
+}
+
+#define CONFIGFS_BIN_ATTR_WO(_pfx, _name, _priv, _maxsz) \
+static struct configfs_bin_attribute _pfx##attr_##_name = { \
+ .cb_attr = { \
+ .ca_name = __stringify(_name), \
+ .ca_mode = S_IWUSR, \
+ .ca_owner = THIS_MODULE, \
+ }, \
+ .cb_private = _priv, \
+ .cb_max_size = _maxsz, \
+ .write = _pfx##_name##_write, \
+}
+
+/*
+ * If allow_link() exists, the item can symlink(2) out to other
+ * items. If the item is a group, it may support mkdir(2).
+ * Groups supply one of make_group() and make_item(). If the
+ * group supports make_group(), one can create group children. If it
+ * supports make_item(), one can create config_item children. make_group()
+ * and make_item() return ERR_PTR() on errors. If it has
+ * default_groups on group->default_groups, it has automatically created
+ * group children. default_groups may coexist alongsize make_group() or
+ * make_item(), but if the group wishes to have only default_groups
+ * children (disallowing mkdir(2)), it need not provide either function.
+ * If the group has commit(), it supports pending and committed (active)
+ * items.
+ */
+struct configfs_item_operations {
+ void (*release)(struct config_item *);
+ int (*allow_link)(struct config_item *src, struct config_item *target);
+ void (*drop_link)(struct config_item *src, struct config_item *target);
+};
+
+struct configfs_group_operations {
+ struct config_item *(*make_item)(struct config_group *group, const char *name);
+ struct config_group *(*make_group)(struct config_group *group, const char *name);
+ int (*commit_item)(struct config_item *item);
+ void (*disconnect_notify)(struct config_group *group, struct config_item *item);
+ void (*drop_item)(struct config_group *group, struct config_item *item);
+};
+
+struct configfs_subsystem {
+ struct config_group su_group;
+ struct mutex su_mutex;
+};
+
+static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
+{
+ return group ?
+ container_of(group, struct configfs_subsystem, su_group) :
+ NULL;
+}
+
+int configfs_register_subsystem(struct configfs_subsystem *subsys);
+void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
+
+int configfs_register_group(struct config_group *parent_group,
+ struct config_group *group);
+void configfs_unregister_group(struct config_group *group);
+
+void configfs_remove_default_groups(struct config_group *group);
+
+struct config_group *
+configfs_register_default_group(struct config_group *parent_group,
+ const char *name,
+ const struct config_item_type *item_type);
+void configfs_unregister_default_group(struct config_group *group);
+
+/* These functions can sleep and can alloc with GFP_KERNEL */
+/* WARNING: These cannot be called underneath configfs callbacks!! */
+int configfs_depend_item(struct configfs_subsystem *subsys,
+ struct config_item *target);
+void configfs_undepend_item(struct config_item *target);
+
+/*
+ * These functions can sleep and can alloc with GFP_KERNEL
+ * NOTE: These should be called only underneath configfs callbacks.
+ * NOTE: First parameter is a caller's subsystem, not target's.
+ * WARNING: These cannot be called on newly created item
+ * (in make_group()/make_item() callback)
+ */
+int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys,
+ struct config_item *target);
+
+
+static inline void configfs_undepend_item_unlocked(struct config_item *target)
+{
+ configfs_undepend_item(target);
+}
+
+#endif /* _CONFIGFS_H_ */