+/* Fast test to see if the file is an evenpoll file */
+static inline int is_file_epoll(struct file *f)
+{
+ return f->f_op == &eventpoll_fops;
+}
+
+/* Setup the structure that is used as key for the rb-tree */
+static inline void ep_set_ffd(struct epoll_filefd *ffd,
+ struct file *file, int fd)
+{
+ ffd->file = file;
+ ffd->fd = fd;
+}
+
+/* Compare rb-tree keys */
+static inline int ep_cmp_ffd(struct epoll_filefd *p1,
+ struct epoll_filefd *p2)
+{
+ return (p1->file > p2->file ? +1:
+ (p1->file < p2->file ? -1 : p1->fd - p2->fd));
+}
+
+/* Special initialization for the rb-tree node to detect linkage */
+static inline void ep_rb_initnode(struct rb_node *n)
+{
+ rb_set_parent(n, n);
+}
+
+/* Removes a node from the rb-tree and marks it for a fast is-linked check */
+static inline void ep_rb_erase(struct rb_node *n, struct rb_root *r)
+{
+ rb_erase(n, r);
+ rb_set_parent(n, n);
+}
+
+/* Fast check to verify that the item is linked to the main rb-tree */
+static inline int ep_rb_linked(struct rb_node *n)
+{
+ return rb_parent(n) != n;
+}
+
+/*
+ * Remove the item from the list and perform its initialization.
+ * This is useful for us because we can test if the item is linked
+ * using "ep_is_linked(p)".
+ */
+static inline void ep_list_del(struct list_head *p)
+{
+ list_del(p);
+ INIT_LIST_HEAD(p);
+}
+
+/* Tells us if the item is currently linked */
+static inline int ep_is_linked(struct list_head *p)
+{
+ return !list_empty(p);
+}
+
+/* Get the "struct epitem" from a wait queue pointer */
+static inline struct epitem * ep_item_from_wait(wait_queue_t *p)
+{
+ return container_of(p, struct eppoll_entry, wait)->base;
+}
+
+/* Get the "struct epitem" from an epoll queue wrapper */
+static inline struct epitem * ep_item_from_epqueue(poll_table *p)
+{
+ return container_of(p, struct ep_pqueue, pt)->epi;
+}
+
+/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
+static inline int ep_op_hash_event(int op)
+{
+ return op != EPOLL_CTL_DEL;
+}
+