1 files changed, 17 insertions, 13 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 3247b4208034..65b4b6e7f7bd 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -239,14 +239,16 @@ void __delete_from_page_cache(struct page *page, void *shadow)
 	/* Leave page->index set: truncation lookup relies upon it */
 
 	/* hugetlb pages do not participate in page cache accounting. */
-	if (!PageHuge(page))
-		__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr);
+	if (PageHuge(page))
+		return;
+
+	__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, -nr);
 	if (PageSwapBacked(page)) {
 		__mod_node_page_state(page_pgdat(page), NR_SHMEM, -nr);
 		if (PageTransHuge(page))
 			__dec_node_page_state(page, NR_SHMEM_THPS);
 	} else {
-		VM_BUG_ON_PAGE(PageTransHuge(page) && !PageHuge(page), page);
+		VM_BUG_ON_PAGE(PageTransHuge(page), page);
 	}
 
 	/*
@@ -883,6 +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;
@@ -907,8 +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);
 }
@@ -962,6 +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;
@@ -970,10 +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);
 		}
 
@@ -983,10 +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) {
@@ -996,6 +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);
@@ -1037,7 +1041,7 @@ void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter)
 	unsigned long flags;
 
 	spin_lock_irqsave(&q->lock, flags);
-	__add_wait_queue(q, waiter);
+	__add_wait_queue_entry_tail(q, waiter);
 	SetPageWaiters(page);
 	spin_unlock_irqrestore(&q->lock, flags);
 }