CacheFiles: Permit the page lock state to be monitored

[linux-2.6-omap-h63xx.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index cbc5772e7171fbc7e074dae51743a6f2d5168d91..fc11974f2bee5ea0d39941f3dfce8b0b84910579 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -564,6 +564,24 @@ void wait_on_page_bit(struct page *page, int bit_nr)
 }
 EXPORT_SYMBOL(wait_on_page_bit);
 
+/**
+ * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue
+ * @page - Page defining the wait queue of interest
+ * @waiter - Waiter to add to the queue
+ *
+ * Add an arbitrary @waiter to the wait queue for the nominated @page.
+ */
+void add_page_wait_queue(struct page *page, wait_queue_t *waiter)
+{
+       wait_queue_head_t *q = page_waitqueue(page);
+       unsigned long flags;
+
+       spin_lock_irqsave(&q->lock, flags);
+       __add_wait_queue(q, waiter);
+       spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(add_page_wait_queue);
+
 /**
  * unlock_page - unlock a locked page
  * @page: the page