rmap: anon_vma_prepare: Reduce code duplication by calling anon_vma_chain_link

Reduce code duplication by calling anon_vma_chain_link() from
anon_vma_prepare().

Also move anon_vmal_chain_link() to a more suitable location in the file.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/rmap.c b/mm/rmap.c
index 78cc46b876e678b7b753677c5408c9a314556043..ebeb95e9150ac057504457c82e49e4cc3dd261de 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -120,6 +120,21 @@ static void anon_vma_chain_free(struct anon_vma_chain *anon_vma_chain)
        kmem_cache_free(anon_vma_chain_cachep, anon_vma_chain);
 }
 
+static void anon_vma_chain_link(struct vm_area_struct *vma,
+                               struct anon_vma_chain *avc,
+                               struct anon_vma *anon_vma)
+{
+       avc->vma = vma;
+       avc->anon_vma = anon_vma;
+       list_add(&avc->same_vma, &vma->anon_vma_chain);
+
+       /*
+        * It's critical to add new vmas to the tail of the anon_vma,
+        * see comment in huge_memory.c:__split_huge_page().
+        */
+       list_add_tail(&avc->same_anon_vma, &anon_vma->head);
+}
+
 /**
  * anon_vma_prepare - attach an anon_vma to a memory region
  * @vma: the memory region in question
@@ -175,10 +190,7 @@ int anon_vma_prepare(struct vm_area_struct *vma)
                spin_lock(&mm->page_table_lock);
                if (likely(!vma->anon_vma)) {
                        vma->anon_vma = anon_vma;
-                       avc->anon_vma = anon_vma;
-                       avc->vma = vma;
-                       list_add(&avc->same_vma, &vma->anon_vma_chain);
-                       list_add_tail(&avc->same_anon_vma, &anon_vma->head);
+                       anon_vma_chain_link(vma, avc, anon_vma);
                        allocated = NULL;
                        avc = NULL;
                }
@@ -224,21 +236,6 @@ static inline void unlock_anon_vma_root(struct anon_vma *root)
                mutex_unlock(&root->mutex);
 }
 
-static void anon_vma_chain_link(struct vm_area_struct *vma,
-                               struct anon_vma_chain *avc,
-                               struct anon_vma *anon_vma)
-{
-       avc->vma = vma;
-       avc->anon_vma = anon_vma;
-       list_add(&avc->same_vma, &vma->anon_vma_chain);
-
-       /*
-        * It's critical to add new vmas to the tail of the anon_vma,
-        * see comment in huge_memory.c:__split_huge_page().
-        */
-       list_add_tail(&avc->same_anon_vma, &anon_vma->head);
-}
-
 /*
  * Attach the anon_vmas from src to dst.
  * Returns 0 on success, -ENOMEM on failure.