@@ -1980,6 +1980,42 @@ static int ep_autoremove_wake_function(struct wait_queue_entry *wq_entry,
return ret;
}
+static int __epoll_wait_remove(struct eventpoll *ep,
+ struct wait_queue_entry *wait, int timed_out)
+{
+ int eavail;
+
+ /*
+ * We were woken up, thus go and try to harvest some events. If timed
+ * out and still on the wait queue, recheck eavail carefully under
+ * lock, below.
+ */
+ eavail = 1;
+
+ if (!list_empty_careful(&wait->entry)) {
+ write_lock_irq(&ep->lock);
+ /*
+ * If the thread timed out and is not on the wait queue, it
+ * means that the thread was woken up after its timeout expired
+ * before it could reacquire the lock. Thus, when wait.entry is
+ * empty, it needs to harvest events.
+ */
+ if (timed_out)
+ eavail = list_empty(&wait->entry);
+ __remove_wait_queue(&ep->wq, wait);
+ write_unlock_irq(&ep->lock);
+ }
+
+ return eavail;
+}
+
+int epoll_wait_remove(struct file *file, struct wait_queue_entry *wait)
+{
+ if (is_file_epoll(file))
+ return __epoll_wait_remove(file->private_data, wait, false);
+ return -EINVAL;
+}
+
/**
* ep_poll - Retrieves ready events, and delivers them to the caller-supplied
* event buffer.
@@ -2100,27 +2136,7 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
HRTIMER_MODE_ABS);
__set_current_state(TASK_RUNNING);
- /*
- * We were woken up, thus go and try to harvest some events.
- * If timed out and still on the wait queue, recheck eavail
- * carefully under lock, below.
- */
- eavail = 1;
-
- if (!list_empty_careful(&wait.entry)) {
- write_lock_irq(&ep->lock);
- /*
- * If the thread timed out and is not on the wait queue,
- * it means that the thread was woken up after its
- * timeout expired before it could reacquire the lock.
- * Thus, when wait.entry is empty, it needs to harvest
- * events.
- */
- if (timed_out)
- eavail = list_empty(&wait.entry);
- __remove_wait_queue(&ep->wq, &wait);
- write_unlock_irq(&ep->lock);
- }
+ eavail = __epoll_wait_remove(ep, &wait, timed_out);
}
}
@@ -29,6 +29,9 @@ void eventpoll_release_file(struct file *file);
int epoll_wait(struct file *file, struct epoll_event __user *events,
int maxevents, struct timespec64 *to);
+/* Remove wait entry */
+int epoll_wait_remove(struct file *file, struct wait_queue_entry *wait);
+
/*
* This is called from inside fs/file_table.c:__fput() to unlink files
* from the eventpoll interface. We need to have this facility to cleanup
__epoll_wait_remove() is the core helper, it kills a given wait_queue_entry from the eventpoll wait_queue_head. Use it internally, and provide an overall helper, epoll_wait_remove(), which takes a struct file and provides the same functionality. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- fs/eventpoll.c | 58 +++++++++++++++++++++++++-------------- include/linux/eventpoll.h | 3 ++ 2 files changed, 40 insertions(+), 21 deletions(-)