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-rw-r--r--mm/rmap.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 669acb22b572..22ed3f71a674 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -183,7 +183,7 @@ void __init anon_vma_init(void)
*/
static struct anon_vma *page_lock_anon_vma(struct page *page)
{
- struct anon_vma *anon_vma = NULL;
+ struct anon_vma *anon_vma;
unsigned long anon_mapping;
rcu_read_lock();
@@ -195,9 +195,16 @@ static struct anon_vma *page_lock_anon_vma(struct page *page)
anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
spin_lock(&anon_vma->lock);
+ return anon_vma;
out:
rcu_read_unlock();
- return anon_vma;
+ return NULL;
+}
+
+static void page_unlock_anon_vma(struct anon_vma *anon_vma)
+{
+ spin_unlock(&anon_vma->lock);
+ rcu_read_unlock();
}
/*
@@ -333,7 +340,8 @@ static int page_referenced_anon(struct page *page)
if (!mapcount)
break;
}
- spin_unlock(&anon_vma->lock);
+
+ page_unlock_anon_vma(anon_vma);
return referenced;
}
@@ -802,7 +810,8 @@ static int try_to_unmap_anon(struct page *page, int migration)
if (ret == SWAP_FAIL || !page_mapped(page))
break;
}
- spin_unlock(&anon_vma->lock);
+
+ page_unlock_anon_vma(anon_vma);
return ret;
}