1 files changed, 13 insertions, 2 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9e894edc7811..6001ee6347a9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1819,9 +1819,19 @@ int split_huge_page(struct page *page)
 
         BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
         BUG_ON(!PageAnon(page));
-        anon_vma = page_lock_anon_vma_read(page);
+
+        /*
+         * The caller does not necessarily hold an mmap_sem that would prevent
+         * the anon_vma disappearing so we first we take a reference to it
+         * and then lock the anon_vma for write. This is similar to
+         * page_lock_anon_vma_read except the write lock is taken to serialise
+         * against parallel split or collapse operations.
+         */
+        anon_vma = page_get_anon_vma(page);
         if (!anon_vma)
                 goto out;
+        anon_vma_lock_write(anon_vma);
+
         ret = 0;
         if (!PageCompound(page))
                 goto out_unlock;
@@ -1832,7 +1842,8 @@ int split_huge_page(struct page *page)
 
         BUG_ON(PageCompound(page));
 out_unlock:
-        page_unlock_anon_vma_read(anon_vma);
+        anon_vma_unlock(anon_vma);
+        put_anon_vma(anon_vma);
 out:
         return ret;
 }