android_kernel_motorola_sm6225/include/linux/inotify.h
Amy Griffis 3ca10067f7 [PATCH] inotify (4/5): allow watch removal from event handler
Allow callers to remove watches from their event handler via
inotify_remove_watch_locked().  This functionality can be used to
achieve IN_ONESHOT-like functionality for a subset of events in the
mask.

Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Acked-by: Robert Love <rml@novell.com>
Acked-by: John McCutchan <john@johnmccutchan.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-06-20 05:25:19 -04:00

227 lines
7 KiB
C

/*
* 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 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 */