[GitHub/moto-9609/android_kernel_motorola_exynos9610.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 dentry;
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_ACTIVATED	= 0x0010,
	KERNFS_NS		= 0x0020,
	KERNFS_HAS_SEQ_SHOW	= 0x0040,
	KERNFS_HAS_MMAP		= 0x0080,
	KERNFS_LOCKDEP		= 0x0100,
	KERNFS_STATIC_NAME	= 0x0200,
	KERNFS_SUICIDAL		= 0x0400,
	KERNFS_SUICIDED		= 0x0800,
};

/* @flags for kernfs_create_root() */
enum kernfs_root_flag {
	KERNFS_ROOT_CREATE_DEACTIVATED = 0x0001,
};

/* 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;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
	/*
	 * Use kernfs_get_parent() and kernfs_name/path() instead of
	 * accessing the following two fields directly.  If the node is
	 * never moved to a different parent, it is safe to access the
	 * parent directly.
	 */
	struct kernfs_node	*parent;
	const char		*name;

	struct rb_node		rb;

	const void		*ns;	/* namespace tag */
	unsigned int		hash;	/* ns + name hash */
	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_syscall_ops may be specified on kernfs_create_root() to support
 * 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.  An active reference is held for each
 * kernfs_node parameter.
 */
struct kernfs_syscall_ops {
	int (*remount_fs)(struct kernfs_root *root, int *flags, char *data);
	int (*show_options)(struct seq_file *sf, struct kernfs_root *root);

	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;
	unsigned int		flags;	/* KERNFS_ROOT_* flags */

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

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

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

	size_t			atomic_write_len;
	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.  If atomic_write_len
	 * is not set, a write larger than PAGE_SIZE results in partial
	 * operations of PAGE_SIZE chunks.  If atomic_write_len is set,
	 * writes upto the specified size are executed atomically but
	 * larger ones are rejected with -E2BIG.
	 */
	size_t atomic_write_len;
	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_KERNFS

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;
}

int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen);
char * __must_check kernfs_path(struct kernfs_node *kn, char *buf,
				size_t buflen);
void pr_cont_kernfs_name(struct kernfs_node *kn);
void pr_cont_kernfs_path(struct kernfs_node *kn);
struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn);
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_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);

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_activate(struct kernfs_node *kn);
void kernfs_remove(struct kernfs_node *kn);
void kernfs_break_active_protection(struct kernfs_node *kn);
void kernfs_unbreak_active_protection(struct kernfs_node *kn);
bool kernfs_remove_self(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, bool *new_sb_created,
			       const void *ns);
void kernfs_kill_sb(struct super_block *sb);

void kernfs_init(void);

#else	/* CONFIG_KERNFS */

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 int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)
{ return -ENOSYS; }

static inline char * __must_check kernfs_path(struct kernfs_node *kn, char *buf,
					      size_t buflen)
{ return NULL; }

static inline void pr_cont_kernfs_name(struct kernfs_node *kn) { }
static inline void pr_cont_kernfs_path(struct kernfs_node *kn) { }

static inline struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn)
{ return NULL; }

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_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)
{ 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_activate(struct kernfs_node *kn) { }

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

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

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, bool *new_sb_created, 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_KERNFS */

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 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, bool *new_sb_created)
{
	return kernfs_mount_ns(fs_type, flags, root, new_sb_created, 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>
abd54f02	18	#include <linux/wait.h>
879f40d1	19
5d60418e	20	struct file;
917f56ca	21	struct dentry;
5d60418e	22	struct iattr;
dd8a5b03 TH	23	struct seq_file;
dd8a5b03 TH	24	struct vm_area_struct;
4b93dc9b TH	25	struct super_block;
4b93dc9b TH	26	struct file_system_type;
5d60418e	27
c525aadd TH	28	struct kernfs_open_node;
c525aadd TH	29	struct kernfs_iattrs;
cf9e5a73 TH	30
cf9e5a73 TH	31	enum kernfs_node_type {
df23fc39 TH	32	KERNFS_DIR = 0x0001,
	33	KERNFS_FILE = 0x0002,
	34	KERNFS_LINK = 0x0004,
cf9e5a73 TH	35	};
cf9e5a73 TH	36
df23fc39	37	#define KERNFS_TYPE_MASK 0x000f
df23fc39	38	#define KERNFS_FLAG_MASK ~KERNFS_TYPE_MASK
cf9e5a73 TH	39
cf9e5a73 TH	40	enum kernfs_node_flag {
d35258ef	41	KERNFS_ACTIVATED = 0x0010,
df23fc39 TH	42	KERNFS_NS = 0x0020,
	43	KERNFS_HAS_SEQ_SHOW = 0x0040,
	44	KERNFS_HAS_MMAP = 0x0080,
	45	KERNFS_LOCKDEP = 0x0100,
2063d608	46	KERNFS_STATIC_NAME = 0x0200,
6b0afc2a TH	47	KERNFS_SUICIDAL = 0x0400,
6b0afc2a TH	48	KERNFS_SUICIDED = 0x0800,
cf9e5a73 TH	49	};
cf9e5a73 TH	50
d35258ef TH	51	/* @flags for kernfs_create_root() */
	52	enum kernfs_root_flag {
	53	KERNFS_ROOT_CREATE_DEACTIVATED = 0x0001,
	54	};
	55
324a56e1 TH	56	/* type-specific structures for kernfs_node union members */
324a56e1 TH	57	struct kernfs_elem_dir {
cf9e5a73	58	unsigned long subdirs;
adc5e8b5	59	/* children rbtree starts here and goes through kn->rb */
cf9e5a73 TH	60	struct rb_root children;
	61
	62	/*
	63	* The kernfs hierarchy this directory belongs to. This fits
324a56e1	64	* better directly in kernfs_node but is here to save space.
cf9e5a73 TH	65	*/
	66	struct kernfs_root *root;
	67	};
	68
324a56e1 TH	69	struct kernfs_elem_symlink {
324a56e1 TH	70	struct kernfs_node *target_kn;
cf9e5a73 TH	71	};
cf9e5a73 TH	72
324a56e1	73	struct kernfs_elem_attr {
cf9e5a73	74	const struct kernfs_ops *ops;
c525aadd	75	struct kernfs_open_node *open;
cf9e5a73 TH	76	loff_t size;
	77	};
	78
	79	/*
324a56e1 TH	80	* kernfs_node - the building block of kernfs hierarchy. Each and every
324a56e1 TH	81	* kernfs node is represented by single kernfs_node. Most fields are
cf9e5a73 TH	82	* private to kernfs and shouldn't be accessed directly by kernfs users.
cf9e5a73 TH	83	*
324a56e1 TH	84	* As long as s_count reference is held, the kernfs_node itself is
	85	* accessible. Dereferencing elem or any other outer entity requires
	86	* active reference.
cf9e5a73	87	*/
324a56e1	88	struct kernfs_node {
adc5e8b5 TH	89	atomic_t count;
adc5e8b5 TH	90	atomic_t active;
cf9e5a73 TH	91	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	92	struct lockdep_map dep_map;
	93	#endif
3eef34ad TH	94	/*
	95	* Use kernfs_get_parent() and kernfs_name/path() instead of
	96	* accessing the following two fields directly. If the node is
	97	* never moved to a different parent, it is safe to access the
	98	* parent directly.
	99	*/
adc5e8b5 TH	100	struct kernfs_node *parent;
adc5e8b5 TH	101	const char *name;
cf9e5a73	102
adc5e8b5	103	struct rb_node rb;
cf9e5a73	104
adc5e8b5	105	const void ns; / namespace tag */
9b0925a6	106	unsigned int hash; /* ns + name hash */
cf9e5a73	107	union {
adc5e8b5 TH	108	struct kernfs_elem_dir dir;
	109	struct kernfs_elem_symlink symlink;
	110	struct kernfs_elem_attr attr;
cf9e5a73 TH	111	};
	112
	113	void *priv;
	114
adc5e8b5 TH	115	unsigned short flags;
	116	umode_t mode;
	117	unsigned int ino;
c525aadd	118	struct kernfs_iattrs *iattr;
cf9e5a73	119	};
b8441ed2	120
80b9bbef	121	/*
90c07c89 TH	122	* kernfs_syscall_ops may be specified on kernfs_create_root() to support
	123	* syscalls. These optional callbacks are invoked on the matching syscalls
	124	* and can perform any kernfs operations which don't necessarily have to be
	125	* the exact operation requested. An active reference is held for each
	126	* kernfs_node parameter.
80b9bbef	127	*/
90c07c89	128	struct kernfs_syscall_ops {
6a7fed4e TH	129	int (remount_fs)(struct kernfs_root root, int flags, char data);
	130	int (show_options)(struct seq_file sf, struct kernfs_root *root);
	131
80b9bbef TH	132	int (mkdir)(struct kernfs_node parent, const char *name,
	133	umode_t mode);
	134	int (rmdir)(struct kernfs_node kn);
	135	int (rename)(struct kernfs_node kn, struct kernfs_node *new_parent,
	136	const char *new_name);
	137	};
	138
ba7443bc TH	139	struct kernfs_root {
ba7443bc TH	140	/* published fields */
324a56e1	141	struct kernfs_node *kn;
d35258ef	142	unsigned int flags; /* KERNFS_ROOT_* flags */
bc755553 TH	143
	144	/* private fields, do not use outside kernfs proper */
	145	struct ida ino_ida;
90c07c89	146	struct kernfs_syscall_ops *syscall_ops;
abd54f02	147	wait_queue_head_t deactivate_waitq;
ba7443bc TH	148	};
ba7443bc TH	149
c525aadd	150	struct kernfs_open_file {
dd8a5b03	151	/* published fields */
324a56e1	152	struct kernfs_node *kn;
dd8a5b03	153	struct file *file;
2536390d	154	void *priv;
dd8a5b03 TH	155
	156	/* private fields, do not use outside kernfs proper */
	157	struct mutex mutex;
	158	int event;
	159	struct list_head list;
	160
b7ce40cf	161	size_t atomic_write_len;
dd8a5b03 TH	162	bool mmapped;
	163	const struct vm_operations_struct *vm_ops;
	164	};
	165
f6acf8bb TH	166	struct kernfs_ops {
	167	/*
	168	* Read is handled by either seq_file or raw_read().
	169	*
d19b9846 TH	170	* If seq_show() is present, seq_file path is active. Other seq
	171	* operations are optional and if not implemented, the behavior is
	172	* equivalent to single_open(). @sf->private points to the
c525aadd	173	* associated kernfs_open_file.
f6acf8bb TH	174	*
	175	* read() is bounced through kernel buffer and a read larger than
	176	* PAGE_SIZE results in partial operation of PAGE_SIZE.
	177	*/
	178	int (seq_show)(struct seq_file sf, void *v);
d19b9846 TH	179
	180	void (seq_start)(struct seq_file sf, loff_t ppos);
	181	void (seq_next)(struct seq_file sf, void v, loff_t *ppos);
	182	void (seq_stop)(struct seq_file sf, void *v);
f6acf8bb	183
c525aadd	184	ssize_t (read)(struct kernfs_open_file of, char *buf, size_t bytes,
f6acf8bb TH	185	loff_t off);
	186
	187	/*
4d3773c4 TH	188	* write() is bounced through kernel buffer. If atomic_write_len
	189	* is not set, a write larger than PAGE_SIZE results in partial
	190	* operations of PAGE_SIZE chunks. If atomic_write_len is set,
	191	* writes upto the specified size are executed atomically but
	192	* larger ones are rejected with -E2BIG.
f6acf8bb	193	*/
4d3773c4	194	size_t atomic_write_len;
c525aadd	195	ssize_t (write)(struct kernfs_open_file of, char *buf, size_t bytes,
f6acf8bb TH	196	loff_t off);
f6acf8bb TH	197
c525aadd	198	int (mmap)(struct kernfs_open_file of, struct vm_area_struct *vma);
517e64f5 TH	199
	200	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	201	struct lock_class_key lockdep_key;
	202	#endif
f6acf8bb TH	203	};
f6acf8bb TH	204
ba341d55	205	#ifdef CONFIG_KERNFS
879f40d1	206
df23fc39	207	static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
cf9e5a73	208	{
df23fc39	209	return kn->flags & KERNFS_TYPE_MASK;
cf9e5a73 TH	210	}
	211
	212	/**
	213	* kernfs_enable_ns - enable namespace under a directory
324a56e1	214	* @kn: directory of interest, should be empty
cf9e5a73	215	*
324a56e1 TH	216	* This is to be called right after @kn is created to enable namespace
324a56e1 TH	217	* under it. All children of @kn must have non-NULL namespace tags and
cf9e5a73 TH	218	* only the ones which match the super_block's tag will be visible.
cf9e5a73 TH	219	*/
324a56e1	220	static inline void kernfs_enable_ns(struct kernfs_node *kn)
cf9e5a73	221	{
df23fc39	222	WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
adc5e8b5	223	WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
df23fc39	224	kn->flags \|= KERNFS_NS;
cf9e5a73 TH	225	}
cf9e5a73 TH	226
ac9bba03 TH	227	/**
ac9bba03 TH	228	* kernfs_ns_enabled - test whether namespace is enabled
324a56e1	229	* @kn: the node to test
ac9bba03 TH	230	*
	231	* Test whether namespace filtering is enabled for the children of @ns.
	232	*/
324a56e1	233	static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
ac9bba03	234	{
df23fc39	235	return kn->flags & KERNFS_NS;
ac9bba03 TH	236	}
ac9bba03 TH	237
3eef34ad TH	238	int kernfs_name(struct kernfs_node kn, char buf, size_t buflen);
	239	char * __must_check kernfs_path(struct kernfs_node kn, char buf,
	240	size_t buflen);
	241	void pr_cont_kernfs_name(struct kernfs_node *kn);
	242	void pr_cont_kernfs_path(struct kernfs_node *kn);
	243	struct kernfs_node kernfs_get_parent(struct kernfs_node kn);
324a56e1 TH	244	struct kernfs_node kernfs_find_and_get_ns(struct kernfs_node parent,
	245	const char name, const void ns);
	246	void kernfs_get(struct kernfs_node *kn);
	247	void kernfs_put(struct kernfs_node *kn);
ccf73cf3	248
0c23b225 TH	249	struct kernfs_node kernfs_node_from_dentry(struct dentry dentry);
	250	struct kernfs_root kernfs_root_from_sb(struct super_block sb);
	251
90c07c89	252	struct kernfs_root kernfs_create_root(struct kernfs_syscall_ops scops,
d35258ef	253	unsigned int flags, void *priv);
ba7443bc TH	254	void kernfs_destroy_root(struct kernfs_root *root);
ba7443bc TH	255
324a56e1	256	struct kernfs_node kernfs_create_dir_ns(struct kernfs_node parent,
bb8b9d09 TH	257	const char *name, umode_t mode,
bb8b9d09 TH	258	void priv, const void ns);
2063d608 TH	259	struct kernfs_node __kernfs_create_file(struct kernfs_node parent,
	260	const char *name,
	261	umode_t mode, loff_t size,
	262	const struct kernfs_ops *ops,
	263	void priv, const void ns,
	264	bool name_is_static,
	265	struct lock_class_key *key);
324a56e1 TH	266	struct kernfs_node kernfs_create_link(struct kernfs_node parent,
	267	const char *name,
	268	struct kernfs_node *target);
d35258ef	269	void kernfs_activate(struct kernfs_node *kn);
324a56e1	270	void kernfs_remove(struct kernfs_node *kn);
6b0afc2a TH	271	void kernfs_break_active_protection(struct kernfs_node *kn);
	272	void kernfs_unbreak_active_protection(struct kernfs_node *kn);
	273	bool kernfs_remove_self(struct kernfs_node *kn);
324a56e1	274	int kernfs_remove_by_name_ns(struct kernfs_node parent, const char name,
879f40d1	275	const void *ns);
324a56e1	276	int kernfs_rename_ns(struct kernfs_node kn, struct kernfs_node new_parent,
890ece16	277	const char new_name, const void new_ns);
324a56e1 TH	278	int kernfs_setattr(struct kernfs_node kn, const struct iattr iattr);
324a56e1 TH	279	void kernfs_notify(struct kernfs_node *kn);
879f40d1	280
4b93dc9b TH	281	const void kernfs_super_ns(struct super_block sb);
4b93dc9b TH	282	struct dentry kernfs_mount_ns(struct file_system_type fs_type, int flags,
fed95bab LZ	283	struct kernfs_root root, bool new_sb_created,
fed95bab LZ	284	const void *ns);
4b93dc9b TH	285	void kernfs_kill_sb(struct super_block *sb);
	286
	287	void kernfs_init(void);
	288
ba341d55	289	#else /* CONFIG_KERNFS */
879f40d1	290
df23fc39	291	static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
cf9e5a73 TH	292	{ return 0; } /* whatever */
cf9e5a73 TH	293
324a56e1	294	static inline void kernfs_enable_ns(struct kernfs_node *kn) { }
cf9e5a73	295
324a56e1	296	static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
ac9bba03 TH	297	{ return false; }
ac9bba03 TH	298
3eef34ad TH	299	static inline int kernfs_name(struct kernfs_node kn, char buf, size_t buflen)
	300	{ return -ENOSYS; }
	301
	302	static inline char * __must_check kernfs_path(struct kernfs_node kn, char buf,
	303	size_t buflen)
	304	{ return NULL; }
	305
	306	static inline void pr_cont_kernfs_name(struct kernfs_node *kn) { }
	307	static inline void pr_cont_kernfs_path(struct kernfs_node *kn) { }
	308
	309	static inline struct kernfs_node kernfs_get_parent(struct kernfs_node kn)
	310	{ return NULL; }
	311
324a56e1 TH	312	static inline struct kernfs_node *
324a56e1 TH	313	kernfs_find_and_get_ns(struct kernfs_node parent, const char name,
ccf73cf3 TH	314	const void *ns)
	315	{ return NULL; }
	316
324a56e1 TH	317	static inline void kernfs_get(struct kernfs_node *kn) { }
324a56e1 TH	318	static inline void kernfs_put(struct kernfs_node *kn) { }
ccf73cf3	319
0c23b225 TH	320	static inline struct kernfs_node kernfs_node_from_dentry(struct dentry dentry)
	321	{ return NULL; }
	322
	323	static inline struct kernfs_root kernfs_root_from_sb(struct super_block sb)
	324	{ return NULL; }
	325
80b9bbef	326	static inline struct kernfs_root *
d35258ef TH	327	kernfs_create_root(struct kernfs_syscall_ops *scops, unsigned int flags,
d35258ef TH	328	void *priv)
ba7443bc TH	329	{ return ERR_PTR(-ENOSYS); }
	330
	331	static inline void kernfs_destroy_root(struct kernfs_root *root) { }
	332
324a56e1	333	static inline struct kernfs_node *
bb8b9d09 TH	334	kernfs_create_dir_ns(struct kernfs_node parent, const char name,
bb8b9d09 TH	335	umode_t mode, void priv, const void ns)
93b2b8e4 TH	336	{ return ERR_PTR(-ENOSYS); }
93b2b8e4 TH	337
324a56e1	338	static inline struct kernfs_node *
2063d608 TH	339	__kernfs_create_file(struct kernfs_node parent, const char name,
	340	umode_t mode, loff_t size, const struct kernfs_ops *ops,
	341	void priv, const void ns, bool name_is_static,
	342	struct lock_class_key *key)
496f7394 TH	343	{ return ERR_PTR(-ENOSYS); }
496f7394 TH	344
324a56e1 TH	345	static inline struct kernfs_node *
	346	kernfs_create_link(struct kernfs_node parent, const char name,
	347	struct kernfs_node *target)
5d0e26bb TH	348	{ return ERR_PTR(-ENOSYS); }
5d0e26bb TH	349
d35258ef TH	350	static inline void kernfs_activate(struct kernfs_node *kn) { }
d35258ef TH	351
324a56e1	352	static inline void kernfs_remove(struct kernfs_node *kn) { }
879f40d1	353
6b0afc2a TH	354	static inline bool kernfs_remove_self(struct kernfs_node *kn)
	355	{ return false; }
	356
324a56e1	357	static inline int kernfs_remove_by_name_ns(struct kernfs_node *kn,
879f40d1 TH	358	const char name, const void ns)
	359	{ return -ENOSYS; }
	360
324a56e1 TH	361	static inline int kernfs_rename_ns(struct kernfs_node *kn,
324a56e1 TH	362	struct kernfs_node *new_parent,
890ece16 TH	363	const char new_name, const void new_ns)
	364	{ return -ENOSYS; }
	365
324a56e1	366	static inline int kernfs_setattr(struct kernfs_node *kn,
5d60418e TH	367	const struct iattr *iattr)
	368	{ return -ENOSYS; }
	369
324a56e1	370	static inline void kernfs_notify(struct kernfs_node *kn) { }
024f6471	371
4b93dc9b TH	372	static inline const void kernfs_super_ns(struct super_block sb)
	373	{ return NULL; }
	374
	375	static inline struct dentry *
	376	kernfs_mount_ns(struct file_system_type *fs_type, int flags,
fed95bab	377	struct kernfs_root root, bool new_sb_created, const void *ns)
4b93dc9b TH	378	{ return ERR_PTR(-ENOSYS); }
	379
	380	static inline void kernfs_kill_sb(struct super_block *sb) { }
	381
	382	static inline void kernfs_init(void) { }
	383
ba341d55	384	#endif /* CONFIG_KERNFS */
879f40d1	385
324a56e1 TH	386	static inline struct kernfs_node *
324a56e1 TH	387	kernfs_find_and_get(struct kernfs_node kn, const char name)
ccf73cf3	388	{
324a56e1	389	return kernfs_find_and_get_ns(kn, name, NULL);
ccf73cf3 TH	390	}
ccf73cf3 TH	391
324a56e1	392	static inline struct kernfs_node *
bb8b9d09 TH	393	kernfs_create_dir(struct kernfs_node parent, const char name, umode_t mode,
bb8b9d09 TH	394	void *priv)
93b2b8e4	395	{
bb8b9d09	396	return kernfs_create_dir_ns(parent, name, mode, priv, NULL);
93b2b8e4 TH	397	}
93b2b8e4 TH	398
324a56e1 TH	399	static inline struct kernfs_node *
324a56e1 TH	400	kernfs_create_file_ns(struct kernfs_node parent, const char name,
517e64f5 TH	401	umode_t mode, loff_t size, const struct kernfs_ops *ops,
	402	void priv, const void ns)
	403	{
	404	struct lock_class_key *key = NULL;
	405
	406	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	407	key = (struct lock_class_key *)&ops->lockdep_key;
	408	#endif
2063d608 TH	409	return __kernfs_create_file(parent, name, mode, size, ops, priv, ns,
2063d608 TH	410	false, key);
517e64f5 TH	411	}
517e64f5 TH	412
324a56e1 TH	413	static inline struct kernfs_node *
324a56e1 TH	414	kernfs_create_file(struct kernfs_node parent, const char name, umode_t mode,
496f7394 TH	415	loff_t size, const struct kernfs_ops ops, void priv)
	416	{
	417	return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
	418	}
	419
324a56e1	420	static inline int kernfs_remove_by_name(struct kernfs_node *parent,
879f40d1 TH	421	const char *name)
	422	{
	423	return kernfs_remove_by_name_ns(parent, name, NULL);
	424	}
	425
0c23b225 TH	426	static inline int kernfs_rename(struct kernfs_node *kn,
	427	struct kernfs_node *new_parent,
	428	const char *new_name)
	429	{
	430	return kernfs_rename_ns(kn, new_parent, new_name, NULL);
	431	}
	432
4b93dc9b TH	433	static inline struct dentry *
4b93dc9b TH	434	kernfs_mount(struct file_system_type *fs_type, int flags,
fed95bab	435	struct kernfs_root root, bool new_sb_created)
4b93dc9b	436	{
fed95bab	437	return kernfs_mount_ns(fs_type, flags, root, new_sb_created, NULL);
4b93dc9b TH	438	}
4b93dc9b TH	439
b8441ed2	440	#endif /* __LINUX_KERNFS_H */