1 files changed, 11 insertions, 9 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index a49702445ce0..0b41c8cbeabc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -885,6 +885,7 @@ void __init pagecache_init(void)
         page_writeback_init();
 }
 
+/* This has the same layout as wait_bit_key - see fs/cachefiles/rdwr.c */
 struct wait_page_key {
         struct page *page;
         int bit_nr;
@@ -909,8 +910,10 @@ static int wake_page_function(wait_queue_entry_t *wait, unsigned mode, int sync,
 
         if (wait_page->bit_nr != key->bit_nr)
                 return 0;
+
+        /* Stop walking if it's locked */
         if (test_bit(key->bit_nr, &key->page->flags))
-                return 0;
+                return -1;
 
         return autoremove_wake_function(wait, mode, sync, key);
 }
@@ -964,6 +967,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
         int ret = 0;
 
         init_wait(wait);
+        wait->flags = lock ? WQ_FLAG_EXCLUSIVE : 0;
         wait->func = wake_page_function;
         wait_page.page = page;
         wait_page.bit_nr = bit_nr;
@@ -972,10 +976,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
                 spin_lock_irq(&q->lock);
 
                 if (likely(list_empty(&wait->entry))) {
-                        if (lock)
-                                __add_wait_queue_entry_tail_exclusive(q, wait);
-                        else
-                                __add_wait_queue(q, wait);
+                        __add_wait_queue_entry_tail(q, wait);
                         SetPageWaiters(page);
                 }
 
@@ -985,10 +986,6 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
 
                 if (likely(test_bit(bit_nr, &page->flags))) {
                         io_schedule();
-                        if (unlikely(signal_pending_state(state, current))) {
-                                ret = -EINTR;
-                                break;
-                        }
                 }
 
                 if (lock) {
@@ -998,6 +995,11 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
                         if (!test_bit(bit_nr, &page->flags))
                                 break;
                 }
+
+                if (unlikely(signal_pending_state(state, current))) {
+                        ret = -EINTR;
+                        break;
+                }
         }
 
         finish_wait(q, wait);