1 files changed, 15 insertions, 1 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 8ed709a83eb..33f81252a74 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -612,6 +612,19 @@ void __lock_page_nosync(struct page *page)
                                                         TASK_UNINTERRUPTIBLE);
 }
 
+int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
+                         unsigned int flags)
+{
+        if (!(flags & FAULT_FLAG_ALLOW_RETRY)) {
+                __lock_page(page);
+                return 1;
+        } else {
+                up_read(&mm->mmap_sem);
+                wait_on_page_locked(page);
+                return 0;
+        }
+}
+
 /**
  * find_get_page - find and get a page reference
  * @mapping: the address_space to search
@@ -1550,7 +1563,8 @@ retry_find:
                         goto no_cached_page;
         }
 
-        lock_page(page);
+        if (!lock_page_or_retry(page, vma->vm_mm, vmf->flags))
+                return ret | VM_FAULT_RETRY;
 
         /* Did it get truncated? */
         if (unlikely(page->mapping != mapping)) {