/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
static inline int ep_op_has_event(int op)
{
- return op != EPOLL_CTL_DEL;
+ return op == EPOLL_CTL_ADD || op == EPOLL_CTL_MOD;
}
/* Initialize the poll safe wake up structure */
return 0;
}
+/*
+ * Disables a "struct epitem" in the eventpoll set. Returns -EBUSY if the item
+ * had no event flags set, indicating that another thread may be currently
+ * handling that item's events (in the case that EPOLLONESHOT was being
+ * used). Otherwise a zero result indicates that the item has been disabled
+ * from receiving events. A disabled item may be re-enabled via
+ * EPOLL_CTL_MOD. Must be called with "mtx" held.
+ */
+static int ep_disable(struct eventpoll *ep, struct epitem *epi)
+{
+ int result = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ep->lock, flags);
+ if (epi->event.events & ~EP_PRIVATE_BITS) {
+ if (ep_is_linked(&epi->rdllink))
+ list_del_init(&epi->rdllink);
+ /* Ensure ep_poll_callback will not add epi back onto ready
+ list: */
+ epi->event.events &= EP_PRIVATE_BITS;
+ }
+ else
+ result = -EBUSY;
+ spin_unlock_irqrestore(&ep->lock, flags);
+
+ return result;
+}
+
static void ep_free(struct eventpoll *ep)
{
struct rb_node *rbp;
rb_insert_color(&epi->rbn, &ep->rbr);
}
-
-
#define PATH_ARR_SIZE 5
/*
* These are the number paths of length 1 to 5, that we are allowing to emanate
} else
error = -ENOENT;
break;
+ case EPOLL_CTL_DISABLE:
+ if (epi)
+ error = ep_disable(ep, epi);
+ else
+ error = -ENOENT;
+ break;
}
mutex_unlock(&ep->mtx);
int, maxevents, int, timeout)
{
int error;
- struct file *file;
+ struct fd f;
struct eventpoll *ep;
/* The maximum number of event must be greater than zero */
return -EINVAL;
/* Verify that the area passed by the user is writeable */
- if (!access_ok(VERIFY_WRITE, events, maxevents * sizeof(struct epoll_event))) {
- error = -EFAULT;
- goto error_return;
- }
+ if (!access_ok(VERIFY_WRITE, events, maxevents * sizeof(struct epoll_event)))
+ return -EFAULT;
/* Get the "struct file *" for the eventpoll file */
- error = -EBADF;
- file = fget(epfd);
- if (!file)
- goto error_return;
+ f = fdget(epfd);
+ if (!f.file)
+ return -EBADF;
/*
* We have to check that the file structure underneath the fd
* the user passed to us _is_ an eventpoll file.
*/
error = -EINVAL;
- if (!is_file_epoll(file))
+ if (!is_file_epoll(f.file))
goto error_fput;
/*
* At this point it is safe to assume that the "private_data" contains
* our own data structure.
*/
- ep = file->private_data;
+ ep = f.file->private_data;
/* Time to fish for events ... */
error = ep_poll(ep, events, maxevents, timeout);
error_fput:
- fput(file);
-error_return:
-
+ fdput(f);
return error;
}