[mirror_ubuntu-bionic-kernel.git] / fs / sysfs / sysfs.h

/*
 * fs/sysfs/sysfs.h - sysfs internal header file
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
 *
 * This file is released under the GPLv2.
 */

#include <linux/lockdep.h>
#include <linux/kobject_ns.h>
#include <linux/fs.h>
#include <linux/rbtree.h>

struct sysfs_open_dirent;

/* type-specific structures for sysfs_dirent->s_* union members */
struct sysfs_elem_dir {
	struct kobject		*kobj;

	unsigned long		subdirs;
	/* children rbtree starts here and goes through sd->s_rb */
	struct rb_root		children;
};

struct sysfs_elem_symlink {
	struct sysfs_dirent	*target_sd;
};

struct sysfs_elem_attr {
	struct attribute	*attr;
	struct sysfs_open_dirent *open;
};

struct sysfs_elem_bin_attr {
	struct bin_attribute	*bin_attr;
	struct hlist_head	buffers;
};

struct sysfs_inode_attrs {
	struct iattr	ia_iattr;
	void		*ia_secdata;
	u32		ia_secdata_len;
};

/*
 * sysfs_dirent - the building block of sysfs hierarchy.  Each and
 * every sysfs node is represented by single sysfs_dirent.
 *
 * As long as s_count reference is held, the sysfs_dirent itself is
 * accessible.  Dereferencing s_elem or any other outer entity
 * requires s_active reference.
 */
struct sysfs_dirent {
	atomic_t		s_count;
	atomic_t		s_active;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
	struct sysfs_dirent	*s_parent;
	const char		*s_name;

	struct rb_node		s_rb;

	union {
		struct completion	*completion;
		struct sysfs_dirent	*removed_list;
	} u;

	const void		*s_ns; /* namespace tag */
	unsigned int		s_hash; /* ns + name hash */
	union {
		struct sysfs_elem_dir		s_dir;
		struct sysfs_elem_symlink	s_symlink;
		struct sysfs_elem_attr		s_attr;
		struct sysfs_elem_bin_attr	s_bin_attr;
	};

	unsigned short		s_flags;
	umode_t 		s_mode;
	unsigned int		s_ino;
	struct sysfs_inode_attrs *s_iattr;
};

#define SD_DEACTIVATED_BIAS		INT_MIN

#define SYSFS_TYPE_MASK			0x00ff
#define SYSFS_DIR			0x0001
#define SYSFS_KOBJ_ATTR			0x0002
#define SYSFS_KOBJ_BIN_ATTR		0x0004
#define SYSFS_KOBJ_LINK			0x0008
#define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF		(SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)

/* identify any namespace tag on sysfs_dirents */
#define SYSFS_NS_TYPE_MASK		0xf00
#define SYSFS_NS_TYPE_SHIFT		8

#define SYSFS_FLAG_MASK			~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
#define SYSFS_FLAG_REMOVED		0x02000

static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
{
	return sd->s_flags & SYSFS_TYPE_MASK;
}

/*
 * Return any namespace tags on this dirent.
 * enum kobj_ns_type is defined in linux/kobject.h
 */
static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
{
	return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
}

#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define sysfs_dirent_init_lockdep(sd)				\
do {								\
	struct attribute *attr = sd->s_attr.attr;		\
	struct lock_class_key *key = attr->key;			\
	if (!key)						\
		key = &attr->skey;				\
								\
	lockdep_init_map(&sd->dep_map, "s_active", key, 0);	\
} while(0)
#else
#define sysfs_dirent_init_lockdep(sd) do {} while(0)
#endif

/*
 * Context structure to be used while adding/removing nodes.
 */
struct sysfs_addrm_cxt {
	struct sysfs_dirent	*parent_sd;
	struct sysfs_dirent	*removed;
};

/*
 * mount.c
 */

/*
 * Each sb is associated with a set of namespace tags (i.e.
 * the network namespace of the task which mounted this sysfs
 * instance).
 */
struct sysfs_super_info {
	void *ns[KOBJ_NS_TYPES];
};
#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
extern struct sysfs_dirent sysfs_root;
extern struct kmem_cache *sysfs_dir_cachep;

/*
 * dir.c
 */
extern struct mutex sysfs_mutex;
extern spinlock_t sysfs_assoc_lock;
extern const struct dentry_operations sysfs_dentry_ops;

extern const struct file_operations sysfs_dir_operations;
extern const struct inode_operations sysfs_dir_inode_operations;

struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
void sysfs_put_active(struct sysfs_dirent *sd);
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
		       struct sysfs_dirent *parent_sd);
int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);

struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
				       const void *ns,
				       const unsigned char *name);
struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
				      const void *ns,
				      const unsigned char *name);
struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);

void release_sysfs_dirent(struct sysfs_dirent *sd);

int sysfs_create_subdir(struct kobject *kobj, const char *name,
			struct sysfs_dirent **p_sd);
void sysfs_remove_subdir(struct sysfs_dirent *sd);

int sysfs_rename(struct sysfs_dirent *sd,
	struct sysfs_dirent *new_parent_sd, const void *ns, const char *new_name);

static inline struct sysfs_dirent *__sysfs_get(struct sysfs_dirent *sd)
{
	if (sd) {
		WARN_ON(!atomic_read(&sd->s_count));
		atomic_inc(&sd->s_count);
	}
	return sd;
}
#define sysfs_get(sd) __sysfs_get(sd)

static inline void __sysfs_put(struct sysfs_dirent *sd)
{
	if (sd && atomic_dec_and_test(&sd->s_count))
		release_sysfs_dirent(sd);
}
#define sysfs_put(sd) __sysfs_put(sd)

/*
 * inode.c
 */
struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd);
void sysfs_evict_inode(struct inode *inode);
int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr);
int sysfs_permission(struct inode *inode, int mask);
int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
		size_t size, int flags);
int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const char *name);
int sysfs_inode_init(void);

/*
 * file.c
 */
extern const struct file_operations sysfs_file_operations;

int sysfs_add_file(struct sysfs_dirent *dir_sd,
		   const struct attribute *attr, int type);

int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
			const struct attribute *attr, int type, umode_t amode);
/*
 * bin.c
 */
extern const struct file_operations bin_fops;
void unmap_bin_file(struct sysfs_dirent *attr_sd);

/*
 * symlink.c
 */
extern const struct inode_operations sysfs_symlink_inode_operations;
Commit	Line	Data
6d66f5cd TH	1	/*
	2	* fs/sysfs/sysfs.h - sysfs internal header file
	3	*
	4	* Copyright (c) 2001-3 Patrick Mochel
	5	* Copyright (c) 2007 SUSE Linux Products GmbH
	6	* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
	7	*
	8	* This file is released under the GPLv2.
	9	*/
	10
846f9974	11	#include <linux/lockdep.h>
57cc7215	12	#include <linux/kobject_ns.h>
ddd29ec6	13	#include <linux/fs.h>
4f72c0ca	14	#include <linux/rbtree.h>
ddd29ec6	15
85a4ffad TH	16	struct sysfs_open_dirent;
85a4ffad TH	17
59f69015	18	/* type-specific structures for sysfs_dirent->s_* union members */
3e519038	19	struct sysfs_elem_dir {
59f69015	20	struct kobject *kobj;
7f9838fd	21
54d20f00	22	unsigned long subdirs;
4e4d6d86 EB	23	/* children rbtree starts here and goes through sd->s_rb */
4e4d6d86 EB	24	struct rb_root children;
3e519038 TH	25	};
	26
	27	struct sysfs_elem_symlink {
59f69015	28	struct sysfs_dirent *target_sd;
3e519038 TH	29	};
	30
	31	struct sysfs_elem_attr {
59f69015	32	struct attribute *attr;
85a4ffad	33	struct sysfs_open_dirent *open;
3e519038 TH	34	};
	35
	36	struct sysfs_elem_bin_attr {
59f69015	37	struct bin_attribute *bin_attr;
e0edd3c6	38	struct hlist_head buffers;
3e519038 TH	39	};
3e519038 TH	40
ddd29ec6 DQ	41	struct sysfs_inode_attrs {
	42	struct iattr ia_iattr;
	43	void *ia_secdata;
	44	u32 ia_secdata_len;
	45	};
	46
0ab66088	47	/*
59f69015 TH	48	* sysfs_dirent - the building block of sysfs hierarchy. Each and
	49	* every sysfs node is represented by single sysfs_dirent.
	50	*
0ab66088 TH	51	* As long as s_count reference is held, the sysfs_dirent itself is
	52	* accessible. Dereferencing s_elem or any other outer entity
	53	* requires s_active reference.
	54	*/
d56c3eae AR	55	struct sysfs_dirent {
d56c3eae AR	56	atomic_t s_count;
8619f979	57	atomic_t s_active;
846f9974 EB	58	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	59	struct lockdep_map dep_map;
	60	#endif
59f69015	61	struct sysfs_dirent *s_parent;
59f69015	62	const char *s_name;
3e519038	63
4e4d6d86	64	struct rb_node s_rb;
4f72c0ca	65
58f2a4c7 MP	66	union {
	67	struct completion *completion;
	68	struct sysfs_dirent *removed_list;
	69	} u;
	70
be867b19	71	const void s_ns; / namespace tag */
4e4d6d86	72	unsigned int s_hash; /* ns + name hash */
3e519038	73	union {
b1fc3d61 TH	74	struct sysfs_elem_dir s_dir;
	75	struct sysfs_elem_symlink s_symlink;
	76	struct sysfs_elem_attr s_attr;
	77	struct sysfs_elem_bin_attr s_bin_attr;
	78	};
3e519038	79
15a33824	80	unsigned short s_flags;
faef2b6c	81	umode_t s_mode;
cafa6b5d	82	unsigned int s_ino;
ddd29ec6	83	struct sysfs_inode_attrs *s_iattr;
d56c3eae	84	};
1da177e4	85
59f69015	86	#define SD_DEACTIVATED_BIAS INT_MIN
0ab66088	87
59f69015	88	#define SYSFS_TYPE_MASK 0x00ff
dc2f75f0 TH	89	#define SYSFS_DIR 0x0001
	90	#define SYSFS_KOBJ_ATTR 0x0002
	91	#define SYSFS_KOBJ_BIN_ATTR 0x0004
	92	#define SYSFS_KOBJ_LINK 0x0008
59f69015	93	#define SYSFS_COPY_NAME (SYSFS_DIR \| SYSFS_KOBJ_LINK)
a2db6842	94	#define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR \| SYSFS_KOBJ_BIN_ATTR)
59f69015	95
be867b19	96	/* identify any namespace tag on sysfs_dirents */
15a33824	97	#define SYSFS_NS_TYPE_MASK 0xf00
3ff195b0 EB	98	#define SYSFS_NS_TYPE_SHIFT 8
	99
	100	#define SYSFS_FLAG_MASK ~(SYSFS_NS_TYPE_MASK\|SYSFS_TYPE_MASK)
15a33824	101	#define SYSFS_FLAG_REMOVED 0x02000
59f69015 TH	102
	103	static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
	104	{
	105	return sd->s_flags & SYSFS_TYPE_MASK;
	106	}
	107
be867b19 SH	108	/*
	109	* Return any namespace tags on this dirent.
	110	* enum kobj_ns_type is defined in linux/kobject.h
	111	*/
3ff195b0 EB	112	static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
	113	{
	114	return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
	115	}
	116
846f9974 EB	117	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	118	#define sysfs_dirent_init_lockdep(sd) \
	119	do { \
6992f533 EB	120	struct attribute *attr = sd->s_attr.attr; \
	121	struct lock_class_key *key = attr->key; \
	122	if (!key) \
	123	key = &attr->skey; \
846f9974	124	\
6992f533	125	lockdep_init_map(&sd->dep_map, "s_active", key, 0); \
846f9974 EB	126	} while(0)
	127	#else
	128	#define sysfs_dirent_init_lockdep(sd) do {} while(0)
	129	#endif
	130
59f69015 TH	131	/*
	132	* Context structure to be used while adding/removing nodes.
	133	*/
fb6896da TH	134	struct sysfs_addrm_cxt {
fb6896da TH	135	struct sysfs_dirent *parent_sd;
fb6896da	136	struct sysfs_dirent *removed;
fb6896da TH	137	};
fb6896da TH	138
59f69015 TH	139	/*
	140	* mount.c
	141	*/
be867b19 SH	142
	143	/*
	144	* Each sb is associated with a set of namespace tags (i.e.
	145	* the network namespace of the task which mounted this sysfs
	146	* instance).
	147	*/
9e7fdd25	148	struct sysfs_super_info {
a685e089	149	void *ns[KOBJ_NS_TYPES];
9e7fdd25 EB	150	};
9e7fdd25 EB	151	#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
51225039	152	extern struct sysfs_dirent sysfs_root;
e18b890b	153	extern struct kmem_cache *sysfs_dir_cachep;
1da177e4	154
59f69015 TH	155	/*
	156	* dir.c
	157	*/
3007e997	158	extern struct mutex sysfs_mutex;
59f69015	159	extern spinlock_t sysfs_assoc_lock;
469796d1	160	extern const struct dentry_operations sysfs_dentry_ops;
59f69015	161
4b6f5d20	162	extern const struct file_operations sysfs_dir_operations;
c5ef1c42	163	extern const struct inode_operations sysfs_dir_inode_operations;
1da177e4	164
59f69015	165	struct dentry sysfs_get_dentry(struct sysfs_dirent sd);
e72ceb8c EB	166	struct sysfs_dirent sysfs_get_active(struct sysfs_dirent sd);
e72ceb8c EB	167	void sysfs_put_active(struct sysfs_dirent *sd);
59f69015 TH	168	void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
59f69015 TH	169	struct sysfs_dirent *parent_sd);
36ce6dad	170	int __sysfs_add_one(struct sysfs_addrm_cxt acxt, struct sysfs_dirent sd);
59f69015 TH	171	int sysfs_add_one(struct sysfs_addrm_cxt acxt, struct sysfs_dirent sd);
	172	void sysfs_remove_one(struct sysfs_addrm_cxt acxt, struct sysfs_dirent sd);
	173	void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);
	174
	175	struct sysfs_dirent sysfs_find_dirent(struct sysfs_dirent parent_sd,
3ff195b0	176	const void *ns,
59f69015 TH	177	const unsigned char *name);
59f69015 TH	178	struct sysfs_dirent sysfs_get_dirent(struct sysfs_dirent parent_sd,
3ff195b0	179	const void *ns,
59f69015 TH	180	const unsigned char *name);
	181	struct sysfs_dirent sysfs_new_dirent(const char name, umode_t mode, int type);
	182
	183	void release_sysfs_dirent(struct sysfs_dirent *sd);
	184
	185	int sysfs_create_subdir(struct kobject kobj, const char name,
	186	struct sysfs_dirent **p_sd);
	187	void sysfs_remove_subdir(struct sysfs_dirent *sd);
	188
ca1bab38	189	int sysfs_rename(struct sysfs_dirent *sd,
3ff195b0	190	struct sysfs_dirent new_parent_sd, const void ns, const char *new_name);
ca1bab38	191
f1282c84	192	static inline struct sysfs_dirent __sysfs_get(struct sysfs_dirent sd)
1da177e4	193	{
0ab66088 TH	194	if (sd) {
	195	WARN_ON(!atomic_read(&sd->s_count));
	196	atomic_inc(&sd->s_count);
	197	}
	198	return sd;
1da177e4	199	}
f1282c84	200	#define sysfs_get(sd) __sysfs_get(sd)
1da177e4	201
f1282c84	202	static inline void __sysfs_put(struct sysfs_dirent *sd)
1da177e4	203	{
0ab66088 TH	204	if (sd && atomic_dec_and_test(&sd->s_count))
	205	release_sysfs_dirent(sd);
	206	}
f1282c84	207	#define sysfs_put(sd) __sysfs_put(sd)
59f69015 TH	208
	209	/*
	210	* inode.c
	211	*/
fac2622b	212	struct inode sysfs_get_inode(struct super_block sb, struct sysfs_dirent *sd);
01cd9fef	213	void sysfs_evict_inode(struct inode *inode);
35df63c4	214	int sysfs_sd_setattr(struct sysfs_dirent sd, struct iattr iattr);
10556cb2	215	int sysfs_permission(struct inode *inode, int mask);
59f69015	216	int sysfs_setattr(struct dentry dentry, struct iattr iattr);
e61ab4ae	217	int sysfs_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat);
ddd29ec6 DQ	218	int sysfs_setxattr(struct dentry dentry, const char name, const void *value,
ddd29ec6 DQ	219	size_t size, int flags);
3ff195b0	220	int sysfs_hash_and_remove(struct sysfs_dirent dir_sd, const void ns, const char *name);
e0bf68dd	221	int sysfs_inode_init(void);
59f69015 TH	222
	223	/*
	224	* file.c
	225	*/
	226	extern const struct file_operations sysfs_file_operations;
	227
	228	int sysfs_add_file(struct sysfs_dirent *dir_sd,
	229	const struct attribute *attr, int type);
	230
0f423895	231	int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
faef2b6c	232	const struct attribute *attr, int type, umode_t amode);
59f69015 TH	233	/*
	234	* bin.c
	235	*/
	236	extern const struct file_operations bin_fops;
e0edd3c6	237	void unmap_bin_file(struct sysfs_dirent *attr_sd);
59f69015 TH	238
	239	/*
	240	* symlink.c
	241	*/
	242	extern const struct inode_operations sysfs_symlink_inode_operations;