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		3bcf3860a4
		
	
	
	
	
		
			
			Al explains that calling dentry_open() with a mnt/dentry pair is only garunteed to be safe if they are already used in an open struct file. To make sure this is the case don't store and use a struct path in fsnotify, always use a struct file. Signed-off-by: Eric Paris <eparis@redhat.com>
		
			
				
	
	
		
			336 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			336 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _LINUX_FS_NOTIFY_H
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| #define _LINUX_FS_NOTIFY_H
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| 
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| /*
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|  * include/linux/fsnotify.h - generic hooks for filesystem notification, to
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|  * reduce in-source duplication from both dnotify and inotify.
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|  *
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|  * We don't compile any of this away in some complicated menagerie of ifdefs.
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|  * Instead, we rely on the code inside to optimize away as needed.
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|  *
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|  * (C) Copyright 2005 Robert Love
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|  */
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| 
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| #include <linux/fsnotify_backend.h>
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| #include <linux/audit.h>
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| #include <linux/slab.h>
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| 
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| /*
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|  * fsnotify_d_instantiate - instantiate a dentry for inode
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|  * Called with dcache_lock held.
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|  */
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| static inline void fsnotify_d_instantiate(struct dentry *dentry,
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| 					  struct inode *inode)
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| {
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| 	__fsnotify_d_instantiate(dentry, inode);
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| }
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| 
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| /* Notify this dentry's parent about a child's events. */
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| static inline void fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
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| {
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| 	if (!dentry)
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| 		dentry = file->f_path.dentry;
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| 
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| 	__fsnotify_parent(file, dentry, mask);
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| }
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| 
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| /* simple call site for access decisions */
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| static inline int fsnotify_perm(struct file *file, int mask)
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| {
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| 	struct inode *inode = file->f_path.dentry->d_inode;
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| 	__u32 fsnotify_mask = 0;
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| 
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| 	if (file->f_mode & FMODE_NONOTIFY)
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| 		return 0;
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| 	if (!(mask & (MAY_READ | MAY_OPEN)))
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| 		return 0;
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| 	if (mask & MAY_OPEN)
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| 		fsnotify_mask = FS_OPEN_PERM;
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| 	else if (mask & MAY_READ)
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| 		fsnotify_mask = FS_ACCESS_PERM;
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| 	else
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| 		BUG();
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| 
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| 	return fsnotify(inode, fsnotify_mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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| }
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| 
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| /*
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|  * fsnotify_d_move - dentry has been moved
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|  * Called with dcache_lock and dentry->d_lock held.
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|  */
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| static inline void fsnotify_d_move(struct dentry *dentry)
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| {
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| 	/*
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| 	 * On move we need to update dentry->d_flags to indicate if the new parent
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| 	 * cares about events from this dentry.
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| 	 */
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| 	__fsnotify_update_dcache_flags(dentry);
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| }
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| 
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| /*
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|  * fsnotify_link_count - inode's link count changed
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|  */
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| static inline void fsnotify_link_count(struct inode *inode)
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| {
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| 	fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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| }
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| 
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| /*
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|  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
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|  */
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| static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
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| 				 const unsigned char *old_name,
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| 				 int isdir, struct inode *target, struct dentry *moved)
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| {
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| 	struct inode *source = moved->d_inode;
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| 	u32 fs_cookie = fsnotify_get_cookie();
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| 	__u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
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| 	__u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
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| 	const unsigned char *new_name = moved->d_name.name;
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| 
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| 	if (old_dir == new_dir)
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| 		old_dir_mask |= FS_DN_RENAME;
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| 
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| 	if (isdir) {
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| 		old_dir_mask |= FS_IN_ISDIR;
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| 		new_dir_mask |= FS_IN_ISDIR;
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| 	}
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| 
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| 	fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie);
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| 	fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie);
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| 
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| 	if (target)
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| 		fsnotify_link_count(target);
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| 
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| 	if (source)
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| 		fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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| 	audit_inode_child(moved, new_dir);
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| }
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| 
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| /*
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|  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
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|  */
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| static inline void fsnotify_inode_delete(struct inode *inode)
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| {
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| 	__fsnotify_inode_delete(inode);
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| }
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| 
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| /*
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|  * fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
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|  */
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| static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
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| {
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| 	__fsnotify_vfsmount_delete(mnt);
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| }
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| 
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| /*
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|  * fsnotify_nameremove - a filename was removed from a directory
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|  */
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| static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
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| {
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| 	__u32 mask = FS_DELETE;
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| 
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| 	if (isdir)
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| 		mask |= FS_IN_ISDIR;
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| 
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| 	fsnotify_parent(NULL, dentry, mask);
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| }
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| 
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| /*
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|  * fsnotify_inoderemove - an inode is going away
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|  */
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| static inline void fsnotify_inoderemove(struct inode *inode)
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| {
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| 	fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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| 	__fsnotify_inode_delete(inode);
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| }
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| 
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| /*
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|  * fsnotify_create - 'name' was linked in
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|  */
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| static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
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| {
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| 	audit_inode_child(dentry, inode);
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| 
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| 	fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
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| }
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| 
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| /*
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|  * fsnotify_link - new hardlink in 'inode' directory
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|  * Note: We have to pass also the linked inode ptr as some filesystems leave
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|  *   new_dentry->d_inode NULL and instantiate inode pointer later
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|  */
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| static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
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| {
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| 	fsnotify_link_count(inode);
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| 	audit_inode_child(new_dentry, dir);
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| 
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| 	fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
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| }
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| 
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| /*
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|  * fsnotify_mkdir - directory 'name' was created
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|  */
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| static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
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| {
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| 	__u32 mask = (FS_CREATE | FS_IN_ISDIR);
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| 	struct inode *d_inode = dentry->d_inode;
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| 
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| 	audit_inode_child(dentry, inode);
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| 
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| 	fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
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| }
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| 
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| /*
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|  * fsnotify_access - file was read
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|  */
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| static inline void fsnotify_access(struct file *file)
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| {
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| 	struct inode *inode = file->f_path.dentry->d_inode;
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| 	__u32 mask = FS_ACCESS;
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| 
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| 	if (S_ISDIR(inode->i_mode))
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| 		mask |= FS_IN_ISDIR;
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| 
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| 	if (!(file->f_mode & FMODE_NONOTIFY)) {
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| 		fsnotify_parent(file, NULL, mask);
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| 		fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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| 	}
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| }
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| 
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| /*
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|  * fsnotify_modify - file was modified
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|  */
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| static inline void fsnotify_modify(struct file *file)
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| {
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| 	struct inode *inode = file->f_path.dentry->d_inode;
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| 	__u32 mask = FS_MODIFY;
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| 
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| 	if (S_ISDIR(inode->i_mode))
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| 		mask |= FS_IN_ISDIR;
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| 
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| 	if (!(file->f_mode & FMODE_NONOTIFY)) {
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| 		fsnotify_parent(file, NULL, mask);
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| 		fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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| 	}
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| }
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| 
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| /*
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|  * fsnotify_open - file was opened
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|  */
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| static inline void fsnotify_open(struct file *file)
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| {
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| 	struct inode *inode = file->f_path.dentry->d_inode;
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| 	__u32 mask = FS_OPEN;
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| 
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| 	if (S_ISDIR(inode->i_mode))
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| 		mask |= FS_IN_ISDIR;
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| 
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| 	if (!(file->f_mode & FMODE_NONOTIFY)) {
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| 		fsnotify_parent(file, NULL, mask);
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| 		fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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| 	}
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| }
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| 
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| /*
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|  * fsnotify_close - file was closed
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|  */
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| static inline void fsnotify_close(struct file *file)
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| {
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| 	struct inode *inode = file->f_path.dentry->d_inode;
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| 	fmode_t mode = file->f_mode;
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| 	__u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
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| 
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| 	if (S_ISDIR(inode->i_mode))
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| 		mask |= FS_IN_ISDIR;
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| 
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| 	if (!(file->f_mode & FMODE_NONOTIFY)) {
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| 		fsnotify_parent(file, NULL, mask);
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| 		fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
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| 	}
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| }
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| 
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| /*
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|  * fsnotify_xattr - extended attributes were changed
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|  */
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| static inline void fsnotify_xattr(struct dentry *dentry)
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| {
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| 	struct inode *inode = dentry->d_inode;
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| 	__u32 mask = FS_ATTRIB;
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| 
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| 	if (S_ISDIR(inode->i_mode))
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| 		mask |= FS_IN_ISDIR;
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| 
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| 	fsnotify_parent(NULL, dentry, mask);
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| 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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| }
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| 
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| /*
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|  * fsnotify_change - notify_change event.  file was modified and/or metadata
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|  * was changed.
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|  */
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| static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
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| {
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| 	struct inode *inode = dentry->d_inode;
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| 	__u32 mask = 0;
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| 
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| 	if (ia_valid & ATTR_UID)
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| 		mask |= FS_ATTRIB;
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| 	if (ia_valid & ATTR_GID)
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| 		mask |= FS_ATTRIB;
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| 	if (ia_valid & ATTR_SIZE)
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| 		mask |= FS_MODIFY;
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| 
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| 	/* both times implies a utime(s) call */
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| 	if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
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| 		mask |= FS_ATTRIB;
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| 	else if (ia_valid & ATTR_ATIME)
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| 		mask |= FS_ACCESS;
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| 	else if (ia_valid & ATTR_MTIME)
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| 		mask |= FS_MODIFY;
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| 
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| 	if (ia_valid & ATTR_MODE)
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| 		mask |= FS_ATTRIB;
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| 
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| 	if (mask) {
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| 		if (S_ISDIR(inode->i_mode))
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| 			mask |= FS_IN_ISDIR;
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| 
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| 		fsnotify_parent(NULL, dentry, mask);
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| 		fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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| 	}
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| }
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| 
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| #if defined(CONFIG_FSNOTIFY)	/* notify helpers */
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| 
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| /*
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|  * fsnotify_oldname_init - save off the old filename before we change it
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|  */
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| static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
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| {
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| 	return kstrdup(name, GFP_KERNEL);
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| }
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| 
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| /*
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|  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
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|  */
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| static inline void fsnotify_oldname_free(const unsigned char *old_name)
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| {
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| 	kfree(old_name);
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| }
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| 
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| #else	/* CONFIG_FSNOTIFY */
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| 
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| static inline const char *fsnotify_oldname_init(const unsigned char *name)
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| {
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| 	return NULL;
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| }
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| 
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| static inline void fsnotify_oldname_free(const unsigned char *old_name)
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| {
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| }
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| 
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| #endif	/*  CONFIG_FSNOTIFY */
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| 
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| #endif	/* _LINUX_FS_NOTIFY_H */
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