ClabureDB: Classified Bug-Reports Database

         struct anon_vma *anon_vma = data;
 
         spin_lock_init(&anon_vma->lock);
         INIT_LIST_HEAD(&anon_vma->head);
 }
 
 void __init anon_vma_init(void)
 {
         anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),
                         0, SLAB_DESTROY_BY_RCU|SLAB_PANIC, anon_vma_ctor);
 }
 
 /*
  * Getting a lock on a stable anon_vma from a page off the LRU is
  * tricky: page_lock_anon_vma rely on RCU to guard against the races.
  */
 struct anon_vma *page_lock_anon_vma(struct page *page)
 {
         struct anon_vma *anon_vma;
         unsigned long anon_mapping;
 
         rcu_read_lock();
         anon_mapping = (unsigned long) page->mapping;
         if (!(anon_mapping & PAGE_MAPPING_ANON))
                 goto out;
         if (!page_mapped(page))
                 goto out;
 
         anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
         spin_lock(&anon_vma->lock);
         return anon_vma;
 out:
         rcu_read_unlock();
         return NULL;
 }
 
 void page_unlock_anon_vma(struct anon_vma *anon_vma)
 {
         spin_unlock(&anon_vma->lock);
         rcu_read_unlock();
 }