[mirror_ubuntu-zesty-kernel.git] / include / linux / kernfs.h

/*
 * kernfs.h - pseudo filesystem decoupled from vfs locking
 *
 * This file is released under the GPLv2.
 */

#ifndef __LINUX_KERNFS_H
#define __LINUX_KERNFS_H

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/idr.h>
#include <linux/lockdep.h>
#include <linux/rbtree.h>
#include <linux/atomic.h>
#include <linux/wait.h>

struct file;
struct iattr;
struct seq_file;
struct vm_area_struct;
struct super_block;
struct file_system_type;

struct kernfs_open_node;
struct kernfs_iattrs;

enum kernfs_node_type {
	KERNFS_DIR		= 0x0001,
	KERNFS_FILE		= 0x0002,
	KERNFS_LINK		= 0x0004,
};

#define KERNFS_TYPE_MASK	0x000f
#define KERNFS_FLAG_MASK	~KERNFS_TYPE_MASK

enum kernfs_node_flag {
	KERNFS_JUST_DEACTIVATED	= 0x0010, /* used to aid lockdep annotation */
	KERNFS_NS		= 0x0020,
	KERNFS_HAS_SEQ_SHOW	= 0x0040,
	KERNFS_HAS_MMAP		= 0x0080,
	KERNFS_LOCKDEP		= 0x0100,
	KERNFS_STATIC_NAME	= 0x0200,
};

/* type-specific structures for kernfs_node union members */
struct kernfs_elem_dir {
	unsigned long		subdirs;
	/* children rbtree starts here and goes through kn->rb */
	struct rb_root		children;

	/*
	 * The kernfs hierarchy this directory belongs to.  This fits
	 * better directly in kernfs_node but is here to save space.
	 */
	struct kernfs_root	*root;
};

struct kernfs_elem_symlink {
	struct kernfs_node	*target_kn;
};

struct kernfs_elem_attr {
	const struct kernfs_ops	*ops;
	struct kernfs_open_node	*open;
	loff_t			size;
};

/*
 * kernfs_node - the building block of kernfs hierarchy.  Each and every
 * kernfs node is represented by single kernfs_node.  Most fields are
 * private to kernfs and shouldn't be accessed directly by kernfs users.
 *
 * As long as s_count reference is held, the kernfs_node itself is
 * accessible.  Dereferencing elem or any other outer entity requires
 * active reference.
 */
struct kernfs_node {
	atomic_t		count;
	atomic_t		active;
	int			deact_depth;
	unsigned int		hash;	/* ns + name hash */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
	/* the following two fields are published */
	struct kernfs_node	*parent;
	const char		*name;

	struct rb_node		rb;

	const void		*ns;	/* namespace tag */
	union {
		struct kernfs_elem_dir		dir;
		struct kernfs_elem_symlink	symlink;
		struct kernfs_elem_attr		attr;
	};

	void			*priv;

	unsigned short		flags;
	umode_t			mode;
	unsigned int		ino;
	struct kernfs_iattrs	*iattr;
};

/*
 * kernfs_dir_ops may be specified on kernfs_create_root() to support
 * directory manipulation syscalls.  These optional callbacks are invoked
 * on the matching syscalls and can perform any kernfs operations which
 * don't necessarily have to be the exact operation requested.
 */
struct kernfs_dir_ops {
	int (*mkdir)(struct kernfs_node *parent, const char *name,
		     umode_t mode);
	int (*rmdir)(struct kernfs_node *kn);
	int (*rename)(struct kernfs_node *kn, struct kernfs_node *new_parent,
		      const char *new_name);
};

struct kernfs_root {
	/* published fields */
	struct kernfs_node	*kn;

	/* private fields, do not use outside kernfs proper */
	struct ida		ino_ida;
	struct kernfs_dir_ops	*dir_ops;
	wait_queue_head_t	deactivate_waitq;
};

struct kernfs_open_file {
	/* published fields */
	struct kernfs_node	*kn;
	struct file		*file;

	/* private fields, do not use outside kernfs proper */
	struct mutex		mutex;
	int			event;
	struct list_head	list;

	bool			mmapped;
	const struct vm_operations_struct *vm_ops;
};

struct kernfs_ops {
	/*
	 * Read is handled by either seq_file or raw_read().
	 *
	 * If seq_show() is present, seq_file path is active.  Other seq
	 * operations are optional and if not implemented, the behavior is
	 * equivalent to single_open().  @sf->private points to the
	 * associated kernfs_open_file.
	 *
	 * read() is bounced through kernel buffer and a read larger than
	 * PAGE_SIZE results in partial operation of PAGE_SIZE.
	 */
	int (*seq_show)(struct seq_file *sf, void *v);

	void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
	void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
	void (*seq_stop)(struct seq_file *sf, void *v);

	ssize_t (*read)(struct kernfs_open_file *of, char *buf, size_t bytes,
			loff_t off);

	/*
	 * write() is bounced through kernel buffer and a write larger than
	 * PAGE_SIZE results in partial operation of PAGE_SIZE.
	 */
	ssize_t (*write)(struct kernfs_open_file *of, char *buf, size_t bytes,
			 loff_t off);

	int (*mmap)(struct kernfs_open_file *of, struct vm_area_struct *vma);

#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lock_class_key	lockdep_key;
#endif
};

#ifdef CONFIG_SYSFS

static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
{
	return kn->flags & KERNFS_TYPE_MASK;
}

/**
 * kernfs_enable_ns - enable namespace under a directory
 * @kn: directory of interest, should be empty
 *
 * This is to be called right after @kn is created to enable namespace
 * under it.  All children of @kn must have non-NULL namespace tags and
 * only the ones which match the super_block's tag will be visible.
 */
static inline void kernfs_enable_ns(struct kernfs_node *kn)
{
	WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
	WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
	kn->flags |= KERNFS_NS;
}

/**
 * kernfs_ns_enabled - test whether namespace is enabled
 * @kn: the node to test
 *
 * Test whether namespace filtering is enabled for the children of @ns.
 */
static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
{
	return kn->flags & KERNFS_NS;
}

struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
					   const char *name, const void *ns);
void kernfs_get(struct kernfs_node *kn);
void kernfs_put(struct kernfs_node *kn);

struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops,
				       void *priv);
void kernfs_destroy_root(struct kernfs_root *root);

struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
					 const char *name, umode_t mode,
					 void *priv, const void *ns);
struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
					 const char *name,
					 umode_t mode, loff_t size,
					 const struct kernfs_ops *ops,
					 void *priv, const void *ns,
					 bool name_is_static,
					 struct lock_class_key *key);
struct kernfs_node *kernfs_create_link(struct kernfs_node *parent,
				       const char *name,
				       struct kernfs_node *target);
void kernfs_deactivate(struct kernfs_node *kn);
void kernfs_reactivate(struct kernfs_node *kn);
void kernfs_deactivate_self(struct kernfs_node *kn);
void kernfs_reactivate_self(struct kernfs_node *kn);
void kernfs_remove(struct kernfs_node *kn);
int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
			     const void *ns);
int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
		     const char *new_name, const void *new_ns);
int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
void kernfs_notify(struct kernfs_node *kn);

const void *kernfs_super_ns(struct super_block *sb);
struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
			       struct kernfs_root *root, const void *ns);
void kernfs_kill_sb(struct super_block *sb);

void kernfs_init(void);

#else	/* CONFIG_SYSFS */

static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
{ return 0; }	/* whatever */

static inline void kernfs_enable_ns(struct kernfs_node *kn) { }

static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
{ return false; }

static inline struct kernfs_node *
kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name,
		       const void *ns)
{ return NULL; }

static inline void kernfs_get(struct kernfs_node *kn) { }
static inline void kernfs_put(struct kernfs_node *kn) { }

static inline struct kernfs_root *
kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv)
{ return ERR_PTR(-ENOSYS); }

static inline void kernfs_destroy_root(struct kernfs_root *root) { }

static inline struct kernfs_node *
kernfs_create_dir_ns(struct kernfs_node *parent, const char *name,
		     umode_t mode, void *priv, const void *ns)
{ return ERR_PTR(-ENOSYS); }

static inline struct kernfs_node *
__kernfs_create_file(struct kernfs_node *parent, const char *name,
		     umode_t mode, loff_t size, const struct kernfs_ops *ops,
		     void *priv, const void *ns, bool name_is_static,
		     struct lock_class_key *key)
{ return ERR_PTR(-ENOSYS); }

static inline struct kernfs_node *
kernfs_create_link(struct kernfs_node *parent, const char *name,
		   struct kernfs_node *target)
{ return ERR_PTR(-ENOSYS); }

static inline void kernfs_remove(struct kernfs_node *kn) { }

static inline int kernfs_remove_by_name_ns(struct kernfs_node *kn,
					   const char *name, const void *ns)
{ return -ENOSYS; }

static inline int kernfs_rename_ns(struct kernfs_node *kn,
				   struct kernfs_node *new_parent,
				   const char *new_name, const void *new_ns)
{ return -ENOSYS; }

static inline int kernfs_setattr(struct kernfs_node *kn,
				 const struct iattr *iattr)
{ return -ENOSYS; }

static inline void kernfs_notify(struct kernfs_node *kn) { }

static inline const void *kernfs_super_ns(struct super_block *sb)
{ return NULL; }

static inline struct dentry *
kernfs_mount_ns(struct file_system_type *fs_type, int flags,
		struct kernfs_root *root, const void *ns)
{ return ERR_PTR(-ENOSYS); }

static inline void kernfs_kill_sb(struct super_block *sb) { }

static inline void kernfs_init(void) { }

#endif	/* CONFIG_SYSFS */

static inline struct kernfs_node *
kernfs_find_and_get(struct kernfs_node *kn, const char *name)
{
	return kernfs_find_and_get_ns(kn, name, NULL);
}

static inline struct kernfs_node *
kernfs_create_dir(struct kernfs_node *parent, const char *name, umode_t mode,
		  void *priv)
{
	return kernfs_create_dir_ns(parent, name, mode, priv, NULL);
}

static inline struct kernfs_node *
kernfs_create_file_ns(struct kernfs_node *parent, const char *name,
		      umode_t mode, loff_t size, const struct kernfs_ops *ops,
		      void *priv, const void *ns)
{
	struct lock_class_key *key = NULL;

#ifdef CONFIG_DEBUG_LOCK_ALLOC
	key = (struct lock_class_key *)&ops->lockdep_key;
#endif
	return __kernfs_create_file(parent, name, mode, size, ops, priv, ns,
				    false, key);
}

static inline struct kernfs_node *
kernfs_create_file(struct kernfs_node *parent, const char *name, umode_t mode,
		   loff_t size, const struct kernfs_ops *ops, void *priv)
{
	return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
}

static inline int kernfs_remove_by_name(struct kernfs_node *parent,
					const char *name)
{
	return kernfs_remove_by_name_ns(parent, name, NULL);
}

static inline struct dentry *
kernfs_mount(struct file_system_type *fs_type, int flags,
	     struct kernfs_root *root)
{
	return kernfs_mount_ns(fs_type, flags, root, NULL);
}

#endif	/* __LINUX_KERNFS_H */
Commit	Line	Data
b8441ed2 TH	1	/*
	2	* kernfs.h - pseudo filesystem decoupled from vfs locking
	3	*
	4	* This file is released under the GPLv2.
	5	*/
	6
	7	#ifndef __LINUX_KERNFS_H
	8	#define __LINUX_KERNFS_H
	9
879f40d1	10	#include <linux/kernel.h>
5d0e26bb	11	#include <linux/err.h>
dd8a5b03 TH	12	#include <linux/list.h>
dd8a5b03 TH	13	#include <linux/mutex.h>
bc755553	14	#include <linux/idr.h>
517e64f5	15	#include <linux/lockdep.h>
cf9e5a73 TH	16	#include <linux/rbtree.h>
cf9e5a73 TH	17	#include <linux/atomic.h>
ea1c472d	18	#include <linux/wait.h>
879f40d1	19
5d60418e TH	20	struct file;
5d60418e TH	21	struct iattr;
dd8a5b03 TH	22	struct seq_file;
dd8a5b03 TH	23	struct vm_area_struct;
4b93dc9b TH	24	struct super_block;
4b93dc9b TH	25	struct file_system_type;
5d60418e	26
c525aadd TH	27	struct kernfs_open_node;
c525aadd TH	28	struct kernfs_iattrs;
cf9e5a73 TH	29
cf9e5a73 TH	30	enum kernfs_node_type {
df23fc39 TH	31	KERNFS_DIR = 0x0001,
	32	KERNFS_FILE = 0x0002,
	33	KERNFS_LINK = 0x0004,
cf9e5a73 TH	34	};
cf9e5a73 TH	35
df23fc39	36	#define KERNFS_TYPE_MASK 0x000f
df23fc39	37	#define KERNFS_FLAG_MASK ~KERNFS_TYPE_MASK
cf9e5a73 TH	38
cf9e5a73 TH	39	enum kernfs_node_flag {
45a140e5	40	KERNFS_JUST_DEACTIVATED = 0x0010, /* used to aid lockdep annotation */
df23fc39 TH	41	KERNFS_NS = 0x0020,
	42	KERNFS_HAS_SEQ_SHOW = 0x0040,
	43	KERNFS_HAS_MMAP = 0x0080,
	44	KERNFS_LOCKDEP = 0x0100,
2063d608	45	KERNFS_STATIC_NAME = 0x0200,
cf9e5a73 TH	46	};
cf9e5a73 TH	47
324a56e1 TH	48	/* type-specific structures for kernfs_node union members */
324a56e1 TH	49	struct kernfs_elem_dir {
cf9e5a73	50	unsigned long subdirs;
adc5e8b5	51	/* children rbtree starts here and goes through kn->rb */
cf9e5a73 TH	52	struct rb_root children;
	53
	54	/*
	55	* The kernfs hierarchy this directory belongs to. This fits
324a56e1	56	* better directly in kernfs_node but is here to save space.
cf9e5a73 TH	57	*/
	58	struct kernfs_root *root;
	59	};
	60
324a56e1 TH	61	struct kernfs_elem_symlink {
324a56e1 TH	62	struct kernfs_node *target_kn;
cf9e5a73 TH	63	};
cf9e5a73 TH	64
324a56e1	65	struct kernfs_elem_attr {
cf9e5a73	66	const struct kernfs_ops *ops;
c525aadd	67	struct kernfs_open_node *open;
cf9e5a73 TH	68	loff_t size;
	69	};
	70
	71	/*
324a56e1 TH	72	* kernfs_node - the building block of kernfs hierarchy. Each and every
324a56e1 TH	73	* kernfs node is represented by single kernfs_node. Most fields are
cf9e5a73 TH	74	* private to kernfs and shouldn't be accessed directly by kernfs users.
cf9e5a73 TH	75	*
324a56e1 TH	76	* As long as s_count reference is held, the kernfs_node itself is
	77	* accessible. Dereferencing elem or any other outer entity requires
	78	* active reference.
cf9e5a73	79	*/
324a56e1	80	struct kernfs_node {
adc5e8b5 TH	81	atomic_t count;
adc5e8b5 TH	82	atomic_t active;
9f010c2a TH	83	int deact_depth;
9f010c2a TH	84	unsigned int hash; /* ns + name hash */
cf9e5a73 TH	85	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	86	struct lockdep_map dep_map;
	87	#endif
	88	/* the following two fields are published */
adc5e8b5 TH	89	struct kernfs_node *parent;
adc5e8b5 TH	90	const char *name;
cf9e5a73	91
adc5e8b5	92	struct rb_node rb;
cf9e5a73	93
adc5e8b5	94	const void ns; / namespace tag */
cf9e5a73	95	union {
adc5e8b5 TH	96	struct kernfs_elem_dir dir;
	97	struct kernfs_elem_symlink symlink;
	98	struct kernfs_elem_attr attr;
cf9e5a73 TH	99	};
	100
	101	void *priv;
	102
adc5e8b5 TH	103	unsigned short flags;
	104	umode_t mode;
	105	unsigned int ino;
c525aadd	106	struct kernfs_iattrs *iattr;
cf9e5a73	107	};
b8441ed2	108
80b9bbef TH	109	/*
	110	* kernfs_dir_ops may be specified on kernfs_create_root() to support
	111	* directory manipulation syscalls. These optional callbacks are invoked
	112	* on the matching syscalls and can perform any kernfs operations which
	113	* don't necessarily have to be the exact operation requested.
	114	*/
	115	struct kernfs_dir_ops {
	116	int (mkdir)(struct kernfs_node parent, const char *name,
	117	umode_t mode);
	118	int (rmdir)(struct kernfs_node kn);
	119	int (rename)(struct kernfs_node kn, struct kernfs_node *new_parent,
	120	const char *new_name);
	121	};
	122
ba7443bc TH	123	struct kernfs_root {
ba7443bc TH	124	/* published fields */
324a56e1	125	struct kernfs_node *kn;
bc755553 TH	126
	127	/* private fields, do not use outside kernfs proper */
	128	struct ida ino_ida;
80b9bbef	129	struct kernfs_dir_ops *dir_ops;
ea1c472d	130	wait_queue_head_t deactivate_waitq;
ba7443bc TH	131	};
ba7443bc TH	132
c525aadd	133	struct kernfs_open_file {
dd8a5b03	134	/* published fields */
324a56e1	135	struct kernfs_node *kn;
dd8a5b03 TH	136	struct file *file;
	137
	138	/* private fields, do not use outside kernfs proper */
	139	struct mutex mutex;
	140	int event;
	141	struct list_head list;
	142
	143	bool mmapped;
	144	const struct vm_operations_struct *vm_ops;
	145	};
	146
f6acf8bb TH	147	struct kernfs_ops {
	148	/*
	149	* Read is handled by either seq_file or raw_read().
	150	*
d19b9846 TH	151	* If seq_show() is present, seq_file path is active. Other seq
	152	* operations are optional and if not implemented, the behavior is
	153	* equivalent to single_open(). @sf->private points to the
c525aadd	154	* associated kernfs_open_file.
f6acf8bb TH	155	*
	156	* read() is bounced through kernel buffer and a read larger than
	157	* PAGE_SIZE results in partial operation of PAGE_SIZE.
	158	*/
	159	int (seq_show)(struct seq_file sf, void *v);
d19b9846 TH	160
	161	void (seq_start)(struct seq_file sf, loff_t ppos);
	162	void (seq_next)(struct seq_file sf, void v, loff_t *ppos);
	163	void (seq_stop)(struct seq_file sf, void *v);
f6acf8bb	164
c525aadd	165	ssize_t (read)(struct kernfs_open_file of, char *buf, size_t bytes,
f6acf8bb TH	166	loff_t off);
	167
	168	/*
	169	* write() is bounced through kernel buffer and a write larger than
	170	* PAGE_SIZE results in partial operation of PAGE_SIZE.
	171	*/
c525aadd	172	ssize_t (write)(struct kernfs_open_file of, char *buf, size_t bytes,
f6acf8bb TH	173	loff_t off);
f6acf8bb TH	174
c525aadd	175	int (mmap)(struct kernfs_open_file of, struct vm_area_struct *vma);
517e64f5 TH	176
	177	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	178	struct lock_class_key lockdep_key;
	179	#endif
f6acf8bb TH	180	};
f6acf8bb TH	181
879f40d1 TH	182	#ifdef CONFIG_SYSFS
879f40d1 TH	183
df23fc39	184	static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
cf9e5a73	185	{
df23fc39	186	return kn->flags & KERNFS_TYPE_MASK;
cf9e5a73 TH	187	}
	188
	189	/**
	190	* kernfs_enable_ns - enable namespace under a directory
324a56e1	191	* @kn: directory of interest, should be empty
cf9e5a73	192	*
324a56e1 TH	193	* This is to be called right after @kn is created to enable namespace
324a56e1 TH	194	* under it. All children of @kn must have non-NULL namespace tags and
cf9e5a73 TH	195	* only the ones which match the super_block's tag will be visible.
cf9e5a73 TH	196	*/
324a56e1	197	static inline void kernfs_enable_ns(struct kernfs_node *kn)
cf9e5a73	198	{
df23fc39	199	WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
adc5e8b5	200	WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
df23fc39	201	kn->flags \|= KERNFS_NS;
cf9e5a73 TH	202	}
cf9e5a73 TH	203
ac9bba03 TH	204	/**
ac9bba03 TH	205	* kernfs_ns_enabled - test whether namespace is enabled
324a56e1	206	* @kn: the node to test
ac9bba03 TH	207	*
	208	* Test whether namespace filtering is enabled for the children of @ns.
	209	*/
324a56e1	210	static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
ac9bba03	211	{
df23fc39	212	return kn->flags & KERNFS_NS;
ac9bba03 TH	213	}
ac9bba03 TH	214
324a56e1 TH	215	struct kernfs_node kernfs_find_and_get_ns(struct kernfs_node parent,
	216	const char name, const void ns);
	217	void kernfs_get(struct kernfs_node *kn);
	218	void kernfs_put(struct kernfs_node *kn);
ccf73cf3	219
80b9bbef TH	220	struct kernfs_root kernfs_create_root(struct kernfs_dir_ops kdops,
80b9bbef TH	221	void *priv);
ba7443bc TH	222	void kernfs_destroy_root(struct kernfs_root *root);
ba7443bc TH	223
324a56e1	224	struct kernfs_node kernfs_create_dir_ns(struct kernfs_node parent,
bb8b9d09 TH	225	const char *name, umode_t mode,
bb8b9d09 TH	226	void priv, const void ns);
2063d608 TH	227	struct kernfs_node __kernfs_create_file(struct kernfs_node parent,
	228	const char *name,
	229	umode_t mode, loff_t size,
	230	const struct kernfs_ops *ops,
	231	void priv, const void ns,
	232	bool name_is_static,
	233	struct lock_class_key *key);
324a56e1 TH	234	struct kernfs_node kernfs_create_link(struct kernfs_node parent,
	235	const char *name,
	236	struct kernfs_node *target);
9f010c2a TH	237	void kernfs_deactivate(struct kernfs_node *kn);
	238	void kernfs_reactivate(struct kernfs_node *kn);
	239	void kernfs_deactivate_self(struct kernfs_node *kn);
	240	void kernfs_reactivate_self(struct kernfs_node *kn);
324a56e1 TH	241	void kernfs_remove(struct kernfs_node *kn);
324a56e1 TH	242	int kernfs_remove_by_name_ns(struct kernfs_node parent, const char name,
879f40d1	243	const void *ns);
324a56e1	244	int kernfs_rename_ns(struct kernfs_node kn, struct kernfs_node new_parent,
890ece16	245	const char new_name, const void new_ns);
324a56e1 TH	246	int kernfs_setattr(struct kernfs_node kn, const struct iattr iattr);
324a56e1 TH	247	void kernfs_notify(struct kernfs_node *kn);
879f40d1	248
4b93dc9b TH	249	const void kernfs_super_ns(struct super_block sb);
	250	struct dentry kernfs_mount_ns(struct file_system_type fs_type, int flags,
	251	struct kernfs_root root, const void ns);
	252	void kernfs_kill_sb(struct super_block *sb);
	253
	254	void kernfs_init(void);
	255
879f40d1 TH	256	#else /* CONFIG_SYSFS */
879f40d1 TH	257
df23fc39	258	static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
cf9e5a73 TH	259	{ return 0; } /* whatever */
cf9e5a73 TH	260
324a56e1	261	static inline void kernfs_enable_ns(struct kernfs_node *kn) { }
cf9e5a73	262
324a56e1	263	static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
ac9bba03 TH	264	{ return false; }
ac9bba03 TH	265
324a56e1 TH	266	static inline struct kernfs_node *
324a56e1 TH	267	kernfs_find_and_get_ns(struct kernfs_node parent, const char name,
ccf73cf3 TH	268	const void *ns)
	269	{ return NULL; }
	270
324a56e1 TH	271	static inline void kernfs_get(struct kernfs_node *kn) { }
324a56e1 TH	272	static inline void kernfs_put(struct kernfs_node *kn) { }
ccf73cf3	273
80b9bbef TH	274	static inline struct kernfs_root *
80b9bbef TH	275	kernfs_create_root(struct kernfs_dir_ops kdops, void priv)
ba7443bc TH	276	{ return ERR_PTR(-ENOSYS); }
	277
	278	static inline void kernfs_destroy_root(struct kernfs_root *root) { }
	279
324a56e1	280	static inline struct kernfs_node *
bb8b9d09 TH	281	kernfs_create_dir_ns(struct kernfs_node parent, const char name,
bb8b9d09 TH	282	umode_t mode, void priv, const void ns)
93b2b8e4 TH	283	{ return ERR_PTR(-ENOSYS); }
93b2b8e4 TH	284
324a56e1	285	static inline struct kernfs_node *
2063d608 TH	286	__kernfs_create_file(struct kernfs_node parent, const char name,
	287	umode_t mode, loff_t size, const struct kernfs_ops *ops,
	288	void priv, const void ns, bool name_is_static,
	289	struct lock_class_key *key)
496f7394 TH	290	{ return ERR_PTR(-ENOSYS); }
496f7394 TH	291
324a56e1 TH	292	static inline struct kernfs_node *
	293	kernfs_create_link(struct kernfs_node parent, const char name,
	294	struct kernfs_node *target)
5d0e26bb TH	295	{ return ERR_PTR(-ENOSYS); }
5d0e26bb TH	296
324a56e1	297	static inline void kernfs_remove(struct kernfs_node *kn) { }
879f40d1	298
324a56e1	299	static inline int kernfs_remove_by_name_ns(struct kernfs_node *kn,
879f40d1 TH	300	const char name, const void ns)
	301	{ return -ENOSYS; }
	302
324a56e1 TH	303	static inline int kernfs_rename_ns(struct kernfs_node *kn,
324a56e1 TH	304	struct kernfs_node *new_parent,
890ece16 TH	305	const char new_name, const void new_ns)
	306	{ return -ENOSYS; }
	307
324a56e1	308	static inline int kernfs_setattr(struct kernfs_node *kn,
5d60418e TH	309	const struct iattr *iattr)
	310	{ return -ENOSYS; }
	311
324a56e1	312	static inline void kernfs_notify(struct kernfs_node *kn) { }
024f6471	313
4b93dc9b TH	314	static inline const void kernfs_super_ns(struct super_block sb)
	315	{ return NULL; }
	316
	317	static inline struct dentry *
	318	kernfs_mount_ns(struct file_system_type *fs_type, int flags,
	319	struct kernfs_root root, const void ns)
	320	{ return ERR_PTR(-ENOSYS); }
	321
	322	static inline void kernfs_kill_sb(struct super_block *sb) { }
	323
	324	static inline void kernfs_init(void) { }
	325
879f40d1 TH	326	#endif /* CONFIG_SYSFS */
879f40d1 TH	327
324a56e1 TH	328	static inline struct kernfs_node *
324a56e1 TH	329	kernfs_find_and_get(struct kernfs_node kn, const char name)
ccf73cf3	330	{
324a56e1	331	return kernfs_find_and_get_ns(kn, name, NULL);
ccf73cf3 TH	332	}
ccf73cf3 TH	333
324a56e1	334	static inline struct kernfs_node *
bb8b9d09 TH	335	kernfs_create_dir(struct kernfs_node parent, const char name, umode_t mode,
bb8b9d09 TH	336	void *priv)
93b2b8e4	337	{
bb8b9d09	338	return kernfs_create_dir_ns(parent, name, mode, priv, NULL);
93b2b8e4 TH	339	}
93b2b8e4 TH	340
324a56e1 TH	341	static inline struct kernfs_node *
324a56e1 TH	342	kernfs_create_file_ns(struct kernfs_node parent, const char name,
517e64f5 TH	343	umode_t mode, loff_t size, const struct kernfs_ops *ops,
	344	void priv, const void ns)
	345	{
	346	struct lock_class_key *key = NULL;
	347
	348	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	349	key = (struct lock_class_key *)&ops->lockdep_key;
	350	#endif
2063d608 TH	351	return __kernfs_create_file(parent, name, mode, size, ops, priv, ns,
2063d608 TH	352	false, key);
517e64f5 TH	353	}
517e64f5 TH	354
324a56e1 TH	355	static inline struct kernfs_node *
324a56e1 TH	356	kernfs_create_file(struct kernfs_node parent, const char name, umode_t mode,
496f7394 TH	357	loff_t size, const struct kernfs_ops ops, void priv)
	358	{
	359	return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
	360	}
	361
324a56e1	362	static inline int kernfs_remove_by_name(struct kernfs_node *parent,
879f40d1 TH	363	const char *name)
	364	{
	365	return kernfs_remove_by_name_ns(parent, name, NULL);
	366	}
	367
4b93dc9b TH	368	static inline struct dentry *
	369	kernfs_mount(struct file_system_type *fs_type, int flags,
	370	struct kernfs_root *root)
	371	{
	372	return kernfs_mount_ns(fs_type, flags, root, NULL);
	373	}
	374
b8441ed2	375	#endif /* __LINUX_KERNFS_H */