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>

1 files changed, 16 insertions, 19 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 78cc46b876e6..ebeb95e9150a 100644
--- 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.