[mirror_ubuntu-bionic-kernel.git] / include / linux / inotify.h

/*
 * Inode based directory notification for Linux
 *
 * Copyright (C) 2005 John McCutchan
 */

#ifndef _LINUX_INOTIFY_H
#define _LINUX_INOTIFY_H

#include <linux/types.h>

/*
 * struct inotify_event - structure read from the inotify device for each event
 *
 * When you are watching a directory, you will receive the filename for events
 * such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ..., relative to the wd.
 */
struct inotify_event {
	__s32		wd;		/* watch descriptor */
	__u32		mask;		/* watch mask */
	__u32		cookie;		/* cookie to synchronize two events */
	__u32		len;		/* length (including nulls) of name */
	char		name[0];	/* stub for possible name */
};

/* the following are legal, implemented events that user-space can watch for */
#define IN_ACCESS		0x00000001	/* File was accessed */
#define IN_MODIFY		0x00000002	/* File was modified */
#define IN_ATTRIB		0x00000004	/* Metadata changed */
#define IN_CLOSE_WRITE		0x00000008	/* Writtable file was closed */
#define IN_CLOSE_NOWRITE	0x00000010	/* Unwrittable file closed */
#define IN_OPEN			0x00000020	/* File was opened */
#define IN_MOVED_FROM		0x00000040	/* File was moved from X */
#define IN_MOVED_TO		0x00000080	/* File was moved to Y */
#define IN_CREATE		0x00000100	/* Subfile was created */
#define IN_DELETE		0x00000200	/* Subfile was deleted */
#define IN_DELETE_SELF		0x00000400	/* Self was deleted */
#define IN_MOVE_SELF		0x00000800	/* Self was moved */

/* the following are legal events.  they are sent as needed to any watch */
#define IN_UNMOUNT		0x00002000	/* Backing fs was unmounted */
#define IN_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
#define IN_IGNORED		0x00008000	/* File was ignored */

/* helper events */
#define IN_CLOSE		(IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* close */
#define IN_MOVE			(IN_MOVED_FROM | IN_MOVED_TO) /* moves */

/* special flags */
#define IN_ONLYDIR		0x01000000	/* only watch the path if it is a directory */
#define IN_DONT_FOLLOW		0x02000000	/* don't follow a sym link */
#define IN_MASK_ADD		0x20000000	/* add to the mask of an already existing watch */
#define IN_ISDIR		0x40000000	/* event occurred against dir */
#define IN_ONESHOT		0x80000000	/* only send event once */

/*
 * All of the events - we build the list by hand so that we can add flags in
 * the future and not break backward compatibility.  Apps will get only the
 * events that they originally wanted.  Be sure to add new events here!
 */
#define IN_ALL_EVENTS	(IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
			 IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
			 IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF | \
			 IN_MOVE_SELF)

#ifdef __KERNEL__

#include <linux/dcache.h>
#include <linux/fs.h>

/*
 * struct inotify_watch - represents a watch request on a specific inode
 *
 * h_list is protected by ih->mutex of the associated inotify_handle.
 * i_list, mask are protected by inode->inotify_mutex of the associated inode.
 * ih, inode, and wd are never written to once the watch is created.
 *
 * Callers must use the established inotify interfaces to access inotify_watch
 * contents.  The content of this structure is private to the inotify
 * implementation.
 */
struct inotify_watch {
	struct list_head	h_list;	/* entry in inotify_handle's list */
	struct list_head	i_list;	/* entry in inode's list */
	atomic_t		count;	/* reference count */
	struct inotify_handle	*ih;	/* associated inotify handle */
	struct inode		*inode;	/* associated inode */
	__s32			wd;	/* watch descriptor */
	__u32			mask;	/* event mask for this watch */
};

struct inotify_operations {
	void (*handle_event)(struct inotify_watch *, u32, u32, u32,
			     const char *, struct inode *);
	void (*destroy_watch)(struct inotify_watch *);
};

#ifdef CONFIG_INOTIFY

/* Kernel API for producing events */

extern void inotify_d_instantiate(struct dentry *, struct inode *);
extern void inotify_d_move(struct dentry *);
extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
				      const char *, struct inode *);
extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
					      const char *);
extern void inotify_unmount_inodes(struct list_head *);
extern void inotify_inode_is_dead(struct inode *);
extern u32 inotify_get_cookie(void);

/* Kernel Consumer API */

extern struct inotify_handle *inotify_init(const struct inotify_operations *);
extern void inotify_init_watch(struct inotify_watch *);
extern void inotify_destroy(struct inotify_handle *);
extern __s32 inotify_find_watch(struct inotify_handle *, struct inode *,
				struct inotify_watch **);
extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,
				       u32);
extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,
			       struct inode *, __u32);
extern __s32 inotify_clone_watch(struct inotify_watch *, struct inotify_watch *);
extern void inotify_evict_watch(struct inotify_watch *);
extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);
extern int inotify_rm_wd(struct inotify_handle *, __u32);
extern void inotify_remove_watch_locked(struct inotify_handle *,
					struct inotify_watch *);
extern void get_inotify_watch(struct inotify_watch *);
extern void put_inotify_watch(struct inotify_watch *);

#else

static inline void inotify_d_instantiate(struct dentry *dentry,
					struct inode *inode)
{
}

static inline void inotify_d_move(struct dentry *dentry)
{
}

static inline void inotify_inode_queue_event(struct inode *inode,
					     __u32 mask, __u32 cookie,
					     const char *filename,
					     struct inode *n_inode)
{
}

static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
						     __u32 mask, __u32 cookie,
						     const char *filename)
{
}

static inline void inotify_unmount_inodes(struct list_head *list)
{
}

static inline void inotify_inode_is_dead(struct inode *inode)
{
}

static inline u32 inotify_get_cookie(void)
{
	return 0;
}

static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline void inotify_init_watch(struct inotify_watch *watch)
{
}

static inline void inotify_destroy(struct inotify_handle *ih)
{
}

static inline __s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
				       struct inotify_watch **watchp)
{
	return -EOPNOTSUPP;
}

static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,
					      struct inode *inode, u32 mask)
{
	return -EOPNOTSUPP;
}

static inline __s32 inotify_add_watch(struct inotify_handle *ih,
				      struct inotify_watch *watch,
				      struct inode *inode, __u32 mask)
{
	return -EOPNOTSUPP;
}

static inline int inotify_rm_watch(struct inotify_handle *ih,
				   struct inotify_watch *watch)
{
	return -EOPNOTSUPP;
}

static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)
{
	return -EOPNOTSUPP;
}

static inline void inotify_remove_watch_locked(struct inotify_handle *ih,
					       struct inotify_watch *watch)
{
}

static inline void get_inotify_watch(struct inotify_watch *watch)
{
}

static inline void put_inotify_watch(struct inotify_watch *watch)
{
}

#endif	/* CONFIG_INOTIFY */

#endif	/* __KERNEL __ */

#endif	/* _LINUX_INOTIFY_H */
Commit	Line	Data
0eeca283 RL	1	/*
	2	* Inode based directory notification for Linux
	3	*
	4	* Copyright (C) 2005 John McCutchan
	5	*/
	6
	7	#ifndef _LINUX_INOTIFY_H
	8	#define _LINUX_INOTIFY_H
	9
	10	#include <linux/types.h>
	11
	12	/*
	13	* struct inotify_event - structure read from the inotify device for each event
	14	*
	15	* When you are watching a directory, you will receive the filename for events
	16	* such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ..., relative to the wd.
	17	*/
	18	struct inotify_event {
	19	__s32 wd; /* watch descriptor */
	20	__u32 mask; /* watch mask */
	21	__u32 cookie; /* cookie to synchronize two events */
	22	__u32 len; /* length (including nulls) of name */
	23	char name[0]; /* stub for possible name */
	24	};
	25
	26	/* the following are legal, implemented events that user-space can watch for */
	27	#define IN_ACCESS 0x00000001 /* File was accessed */
	28	#define IN_MODIFY 0x00000002 /* File was modified */
	29	#define IN_ATTRIB 0x00000004 /* Metadata changed */
	30	#define IN_CLOSE_WRITE 0x00000008 /* Writtable file was closed */
	31	#define IN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */
	32	#define IN_OPEN 0x00000020 /* File was opened */
	33	#define IN_MOVED_FROM 0x00000040 /* File was moved from X */
	34	#define IN_MOVED_TO 0x00000080 /* File was moved to Y */
	35	#define IN_CREATE 0x00000100 /* Subfile was created */
	36	#define IN_DELETE 0x00000200 /* Subfile was deleted */
	37	#define IN_DELETE_SELF 0x00000400 /* Self was deleted */
89204c40	38	#define IN_MOVE_SELF 0x00000800 /* Self was moved */
0eeca283 RL	39
	40	/* the following are legal events. they are sent as needed to any watch */
	41	#define IN_UNMOUNT 0x00002000 /* Backing fs was unmounted */
	42	#define IN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
	43	#define IN_IGNORED 0x00008000 /* File was ignored */
	44
	45	/* helper events */
	46	#define IN_CLOSE (IN_CLOSE_WRITE \| IN_CLOSE_NOWRITE) /* close */
	47	#define IN_MOVE (IN_MOVED_FROM \| IN_MOVED_TO) /* moves */
	48
	49	/* special flags */
8140a500 JM	50	#define IN_ONLYDIR 0x01000000 /* only watch the path if it is a directory */
8140a500 JM	51	#define IN_DONT_FOLLOW 0x02000000 /* don't follow a sym link */
7ea6040b	52	#define IN_MASK_ADD 0x20000000 /* add to the mask of an already existing watch */
0eeca283 RL	53	#define IN_ISDIR 0x40000000 /* event occurred against dir */
	54	#define IN_ONESHOT 0x80000000 /* only send event once */
	55
	56	/*
	57	* All of the events - we build the list by hand so that we can add flags in
	58	* the future and not break backward compatibility. Apps will get only the
	59	* events that they originally wanted. Be sure to add new events here!
	60	*/
	61	#define IN_ALL_EVENTS (IN_ACCESS \| IN_MODIFY \| IN_ATTRIB \| IN_CLOSE_WRITE \| \
	62	IN_CLOSE_NOWRITE \| IN_OPEN \| IN_MOVED_FROM \| \
89204c40 JM	63	IN_MOVED_TO \| IN_DELETE \| IN_CREATE \| IN_DELETE_SELF \| \
89204c40 JM	64	IN_MOVE_SELF)
0eeca283 RL	65
	66	#ifdef __KERNEL__
	67
	68	#include <linux/dcache.h>
	69	#include <linux/fs.h>
0eeca283	70
2d9048e2 AG	71	/*
	72	* struct inotify_watch - represents a watch request on a specific inode
	73	*
	74	* h_list is protected by ih->mutex of the associated inotify_handle.
	75	* i_list, mask are protected by inode->inotify_mutex of the associated inode.
	76	* ih, inode, and wd are never written to once the watch is created.
	77	*
	78	* Callers must use the established inotify interfaces to access inotify_watch
	79	* contents. The content of this structure is private to the inotify
	80	* implementation.
	81	*/
	82	struct inotify_watch {
	83	struct list_head h_list; /* entry in inotify_handle's list */
	84	struct list_head i_list; /* entry in inode's list */
	85	atomic_t count; /* reference count */
	86	struct inotify_handle ih; / associated inotify handle */
	87	struct inode inode; / associated inode */
	88	__s32 wd; /* watch descriptor */
	89	__u32 mask; /* event mask for this watch */
	90	};
	91
	92	struct inotify_operations {
	93	void (handle_event)(struct inotify_watch , u32, u32, u32,
7c297722	94	const char , struct inode );
2d9048e2 AG	95	void (destroy_watch)(struct inotify_watch );
	96	};
	97
0eeca283 RL	98	#ifdef CONFIG_INOTIFY
0eeca283 RL	99
2d9048e2 AG	100	/* Kernel API for producing events */
2d9048e2 AG	101
c32ccd87 NP	102	extern void inotify_d_instantiate(struct dentry , struct inode );
c32ccd87 NP	103	extern void inotify_d_move(struct dentry *);
0eeca283	104	extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
7c297722	105	const char , struct inode );
0eeca283 RL	106	extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
	107	const char *);
	108	extern void inotify_unmount_inodes(struct list_head *);
	109	extern void inotify_inode_is_dead(struct inode *);
	110	extern u32 inotify_get_cookie(void);
	111
2d9048e2 AG	112	/* Kernel Consumer API */
	113
	114	extern struct inotify_handle inotify_init(const struct inotify_operations );
a9dc971d	115	extern void inotify_init_watch(struct inotify_watch *);
2d9048e2	116	extern void inotify_destroy(struct inotify_handle *);
a9dc971d AG	117	extern __s32 inotify_find_watch(struct inotify_handle , struct inode ,
a9dc971d AG	118	struct inotify_watch **);
2d9048e2 AG	119	extern __s32 inotify_find_update_watch(struct inotify_handle , struct inode ,
	120	u32);
	121	extern __s32 inotify_add_watch(struct inotify_handle , struct inotify_watch ,
	122	struct inode *, __u32);
b9efe8a2	123	extern __s32 inotify_clone_watch(struct inotify_watch , struct inotify_watch );
455434d4	124	extern void inotify_evict_watch(struct inotify_watch *);
a9dc971d	125	extern int inotify_rm_watch(struct inotify_handle , struct inotify_watch );
2d9048e2	126	extern int inotify_rm_wd(struct inotify_handle *, __u32);
3ca10067 AG	127	extern void inotify_remove_watch_locked(struct inotify_handle *,
3ca10067 AG	128	struct inotify_watch *);
2d9048e2 AG	129	extern void get_inotify_watch(struct inotify_watch *);
	130	extern void put_inotify_watch(struct inotify_watch *);
	131
0eeca283 RL	132	#else
0eeca283 RL	133
c32ccd87 NP	134	static inline void inotify_d_instantiate(struct dentry *dentry,
	135	struct inode *inode)
	136	{
	137	}
	138
	139	static inline void inotify_d_move(struct dentry *dentry)
	140	{
	141	}
	142
0eeca283 RL	143	static inline void inotify_inode_queue_event(struct inode *inode,
0eeca283 RL	144	__u32 mask, __u32 cookie,
7c297722 AG	145	const char *filename,
7c297722 AG	146	struct inode *n_inode)
0eeca283 RL	147	{
	148	}
	149
	150	static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
	151	__u32 mask, __u32 cookie,
	152	const char *filename)
	153	{
	154	}
	155
	156	static inline void inotify_unmount_inodes(struct list_head *list)
	157	{
	158	}
	159
	160	static inline void inotify_inode_is_dead(struct inode *inode)
	161	{
	162	}
	163
	164	static inline u32 inotify_get_cookie(void)
	165	{
	166	return 0;
	167	}
	168
2d9048e2 AG	169	static inline struct inotify_handle inotify_init(const struct inotify_operations ops)
	170	{
	171	return ERR_PTR(-EOPNOTSUPP);
	172	}
	173
a9dc971d AG	174	static inline void inotify_init_watch(struct inotify_watch *watch)
	175	{
	176	}
	177
2d9048e2 AG	178	static inline void inotify_destroy(struct inotify_handle *ih)
	179	{
	180	}
	181
a9dc971d AG	182	static inline __s32 inotify_find_watch(struct inotify_handle ih, struct inode inode,
	183	struct inotify_watch **watchp)
	184	{
	185	return -EOPNOTSUPP;
	186	}
	187
2d9048e2 AG	188	static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,
	189	struct inode *inode, u32 mask)
	190	{
	191	return -EOPNOTSUPP;
	192	}
	193
	194	static inline __s32 inotify_add_watch(struct inotify_handle *ih,
	195	struct inotify_watch *watch,
	196	struct inode *inode, __u32 mask)
	197	{
	198	return -EOPNOTSUPP;
	199	}
	200
a9dc971d AG	201	static inline int inotify_rm_watch(struct inotify_handle *ih,
	202	struct inotify_watch *watch)
	203	{
	204	return -EOPNOTSUPP;
	205	}
	206
2d9048e2 AG	207	static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)
	208	{
	209	return -EOPNOTSUPP;
	210	}
	211
3ca10067 AG	212	static inline void inotify_remove_watch_locked(struct inotify_handle *ih,
	213	struct inotify_watch *watch)
	214	{
	215	}
	216
2d9048e2 AG	217	static inline void get_inotify_watch(struct inotify_watch *watch)
	218	{
	219	}
	220
	221	static inline void put_inotify_watch(struct inotify_watch *watch)
	222	{
	223	}
	224
0eeca283 RL	225	#endif /* CONFIG_INOTIFY */
	226
	227	#endif /* __KERNEL __ */
	228
	229	#endif /* _LINUX_INOTIFY_H */