kernfs: implement kernfs_node_from_dentry(), kernfs_root_from_sb() and kernfs_rename()
Implement helpers to determine node from dentry and root from
super_block. Also add a kernfs_rename_ns() wrapper which assumes NULL
namespace. These generally make sense and will be used by cgroup.
v2: Some dummy implementations for !CONFIG_SYSFS was missing. Fixed.
Reported by kbuild test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 9ca0f09..9c89904 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -234,6 +234,9 @@
void kernfs_get(struct kernfs_node *kn);
void kernfs_put(struct kernfs_node *kn);
+struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry);
+struct kernfs_root *kernfs_root_from_sb(struct super_block *sb);
+
struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops,
unsigned int flags, void *priv);
void kernfs_destroy_root(struct kernfs_root *root);
@@ -288,6 +291,12 @@
static inline void kernfs_get(struct kernfs_node *kn) { }
static inline void kernfs_put(struct kernfs_node *kn) { }
+static inline struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry)
+{ return NULL; }
+
+static inline struct kernfs_root *kernfs_root_from_sb(struct super_block *sb)
+{ return NULL; }
+
static inline struct kernfs_root *
kernfs_create_root(struct kernfs_syscall_ops *scops, unsigned int flags,
void *priv)
@@ -388,6 +397,13 @@
return kernfs_remove_by_name_ns(parent, name, NULL);
}
+static inline int kernfs_rename(struct kernfs_node *kn,
+ struct kernfs_node *new_parent,
+ const char *new_name)
+{
+ return kernfs_rename_ns(kn, new_parent, new_name, NULL);
+}
+
static inline struct dentry *
kernfs_mount(struct file_system_type *fs_type, int flags,
struct kernfs_root *root)