trim fsnotify hooks a bit

fsnotify_d_move()/__fsnotify_d_instantiate()/__fsnotify_update_dcache_flags()
are identical to each other, regardless of the config.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/dcache.c

@@ -1769,7 +1769,7 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
 	raw_write_seqcount_begin(&dentry->d_seq);
 	__d_set_inode_and_type(dentry, inode, add_flags);
 	raw_write_seqcount_end(&dentry->d_seq);
-	__fsnotify_d_instantiate(dentry);
+	fsnotify_update_flags(dentry);
 	spin_unlock(&dentry->d_lock);
 }
 
@@ -2563,7 +2563,7 @@ static inline void __d_add(struct dentry *dentry, struct inode *inode)
 		raw_write_seqcount_begin(&dentry->d_seq);
 		__d_set_inode_and_type(dentry, inode, add_flags);
 		raw_write_seqcount_end(&dentry->d_seq);
-		__fsnotify_d_instantiate(dentry);
+		fsnotify_update_flags(dentry);
 	}
 	_d_rehash(dentry);
 	if (dir)
@@ -2853,8 +2853,8 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
 		list_move(&target->d_child, &target->d_parent->d_subdirs);
 		list_move(&dentry->d_child, &dentry->d_parent->d_subdirs);
 		if (exchange)
-			fsnotify_d_move(target);
-		fsnotify_d_move(dentry);
+			fsnotify_update_flags(target);
+		fsnotify_update_flags(dentry);
 	}
 
 	write_seqcount_end(&target->d_seq);

include/linux/fsnotify.h

@@ -51,18 +51,6 @@ static inline int fsnotify_perm(struct file *file, int mask)
 	return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
 }
 
-/*
- * fsnotify_d_move - dentry has been moved
- */
-static inline void fsnotify_d_move(struct dentry *dentry)
-{
-	/*
-	 * On move we need to update dentry->d_flags to indicate if the new parent
-	 * cares about events from this dentry.
-	 */
-	__fsnotify_update_dcache_flags(dentry);
-}
-
 /*
  * fsnotify_link_count - inode's link count changed
  */

include/linux/fsnotify_backend.h

@@ -267,10 +267,8 @@ static inline int fsnotify_inode_watches_children(struct inode *inode)
  * Update the dentry with a flag indicating the interest of its parent to receive
  * filesystem events when those events happens to this dentry->d_inode.
  */
-static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
+static inline void fsnotify_update_flags(struct dentry *dentry)
 {
-	struct dentry *parent;
-
 	assert_spin_locked(&dentry->d_lock);
 
 	/*
@@ -280,21 +278,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
 	 * find our entry, so it will spin until we complete here, and update
 	 * us with the new state.
 	 */
-	parent = dentry->d_parent;
-	if (fsnotify_inode_watches_children(parent->d_inode))
+	if (fsnotify_inode_watches_children(dentry->d_parent->d_inode))
 		dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
 	else
 		dentry->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
 }
 
-/*
- * fsnotify_d_instantiate - instantiate a dentry for inode
- */
-static inline void __fsnotify_d_instantiate(struct dentry *dentry)
-{
-	__fsnotify_update_dcache_flags(dentry);
-}
-
 /* called from fsnotify listeners, such as fanotify or dnotify */
 
 /* create a new group */
@@ -386,10 +375,7 @@ static inline void __fsnotify_inode_delete(struct inode *inode)
 static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
 {}
 
-static inline void __fsnotify_update_dcache_flags(struct dentry *dentry)
-{}
-
-static inline void __fsnotify_d_instantiate(struct dentry *dentry)
+static inline void fsnotify_update_flags(struct dentry *dentry)
 {}
 
 static inline u32 fsnotify_get_cookie(void)