forked from mirrors/linux
3ca10067f7
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>
227 lines
7 KiB
C
227 lines
7 KiB
C
/*
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* Inode based directory notification for Linux
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*
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* Copyright (C) 2005 John McCutchan
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*/
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#ifndef _LINUX_INOTIFY_H
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#define _LINUX_INOTIFY_H
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#include <linux/types.h>
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/*
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* struct inotify_event - structure read from the inotify device for each event
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*
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* When you are watching a directory, you will receive the filename for events
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* such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ..., relative to the wd.
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*/
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struct inotify_event {
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__s32 wd; /* watch descriptor */
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__u32 mask; /* watch mask */
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__u32 cookie; /* cookie to synchronize two events */
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__u32 len; /* length (including nulls) of name */
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char name[0]; /* stub for possible name */
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};
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/* the following are legal, implemented events that user-space can watch for */
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#define IN_ACCESS 0x00000001 /* File was accessed */
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#define IN_MODIFY 0x00000002 /* File was modified */
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#define IN_ATTRIB 0x00000004 /* Metadata changed */
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#define IN_CLOSE_WRITE 0x00000008 /* Writtable file was closed */
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#define IN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */
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#define IN_OPEN 0x00000020 /* File was opened */
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#define IN_MOVED_FROM 0x00000040 /* File was moved from X */
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#define IN_MOVED_TO 0x00000080 /* File was moved to Y */
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#define IN_CREATE 0x00000100 /* Subfile was created */
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#define IN_DELETE 0x00000200 /* Subfile was deleted */
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#define IN_DELETE_SELF 0x00000400 /* Self was deleted */
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#define IN_MOVE_SELF 0x00000800 /* Self was moved */
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/* the following are legal events. they are sent as needed to any watch */
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#define IN_UNMOUNT 0x00002000 /* Backing fs was unmounted */
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#define IN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
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#define IN_IGNORED 0x00008000 /* File was ignored */
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/* helper events */
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#define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* close */
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#define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO) /* moves */
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/* special flags */
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#define IN_ONLYDIR 0x01000000 /* only watch the path if it is a directory */
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#define IN_DONT_FOLLOW 0x02000000 /* don't follow a sym link */
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#define IN_MASK_ADD 0x20000000 /* add to the mask of an already existing watch */
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#define IN_ISDIR 0x40000000 /* event occurred against dir */
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#define IN_ONESHOT 0x80000000 /* only send event once */
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/*
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* All of the events - we build the list by hand so that we can add flags in
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* the future and not break backward compatibility. Apps will get only the
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* events that they originally wanted. Be sure to add new events here!
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*/
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#define IN_ALL_EVENTS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
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IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
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IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF | \
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IN_MOVE_SELF)
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#ifdef __KERNEL__
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#include <linux/dcache.h>
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#include <linux/fs.h>
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/*
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* struct inotify_watch - represents a watch request on a specific inode
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*
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* h_list is protected by ih->mutex of the associated inotify_handle.
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* i_list, mask are protected by inode->inotify_mutex of the associated inode.
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* ih, inode, and wd are never written to once the watch is created.
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*
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* Callers must use the established inotify interfaces to access inotify_watch
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* contents. The content of this structure is private to the inotify
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* implementation.
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*/
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struct inotify_watch {
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struct list_head h_list; /* entry in inotify_handle's list */
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struct list_head i_list; /* entry in inode's list */
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atomic_t count; /* reference count */
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struct inotify_handle *ih; /* associated inotify handle */
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struct inode *inode; /* associated inode */
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__s32 wd; /* watch descriptor */
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__u32 mask; /* event mask for this watch */
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};
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struct inotify_operations {
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void (*handle_event)(struct inotify_watch *, u32, u32, u32,
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const char *, struct inode *);
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void (*destroy_watch)(struct inotify_watch *);
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};
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#ifdef CONFIG_INOTIFY
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/* Kernel API for producing events */
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extern void inotify_d_instantiate(struct dentry *, struct inode *);
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extern void inotify_d_move(struct dentry *);
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extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
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const char *, struct inode *);
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extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
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const char *);
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extern void inotify_unmount_inodes(struct list_head *);
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extern void inotify_inode_is_dead(struct inode *);
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extern u32 inotify_get_cookie(void);
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/* Kernel Consumer API */
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extern struct inotify_handle *inotify_init(const struct inotify_operations *);
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extern void inotify_init_watch(struct inotify_watch *);
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extern void inotify_destroy(struct inotify_handle *);
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extern __s32 inotify_find_watch(struct inotify_handle *, struct inode *,
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struct inotify_watch **);
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extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,
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u32);
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extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,
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struct inode *, __u32);
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extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);
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extern int inotify_rm_wd(struct inotify_handle *, __u32);
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extern void inotify_remove_watch_locked(struct inotify_handle *,
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struct inotify_watch *);
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extern void get_inotify_watch(struct inotify_watch *);
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extern void put_inotify_watch(struct inotify_watch *);
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#else
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static inline void inotify_d_instantiate(struct dentry *dentry,
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struct inode *inode)
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{
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}
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static inline void inotify_d_move(struct dentry *dentry)
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{
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}
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static inline void inotify_inode_queue_event(struct inode *inode,
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__u32 mask, __u32 cookie,
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const char *filename,
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struct inode *n_inode)
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{
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}
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static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
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__u32 mask, __u32 cookie,
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const char *filename)
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{
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}
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static inline void inotify_unmount_inodes(struct list_head *list)
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{
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}
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static inline void inotify_inode_is_dead(struct inode *inode)
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{
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}
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static inline u32 inotify_get_cookie(void)
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{
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return 0;
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}
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static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline void inotify_init_watch(struct inotify_watch *watch)
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{
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}
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static inline void inotify_destroy(struct inotify_handle *ih)
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{
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}
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static inline __s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
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struct inotify_watch **watchp)
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{
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return -EOPNOTSUPP;
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}
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static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,
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struct inode *inode, u32 mask)
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{
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return -EOPNOTSUPP;
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}
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static inline __s32 inotify_add_watch(struct inotify_handle *ih,
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struct inotify_watch *watch,
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struct inode *inode, __u32 mask)
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{
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return -EOPNOTSUPP;
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}
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static inline int inotify_rm_watch(struct inotify_handle *ih,
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struct inotify_watch *watch)
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{
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return -EOPNOTSUPP;
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}
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static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)
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{
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return -EOPNOTSUPP;
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}
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static inline void inotify_remove_watch_locked(struct inotify_handle *ih,
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struct inotify_watch *watch)
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{
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}
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static inline void get_inotify_watch(struct inotify_watch *watch)
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{
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}
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static inline void put_inotify_watch(struct inotify_watch *watch)
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{
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}
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#endif /* CONFIG_INOTIFY */
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#endif /* __KERNEL __ */
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#endif /* _LINUX_INOTIFY_H */
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