mm: change direct call of spin_lock(anon_vma->lock) to inline function

Subsitute a direct call of spin_lock(anon_vma->lock) with an inline
function doing exactly the same.

This makes it easier to do the substitution to the root anon_vma lock in a
following patch.

We will deal with the handful of special locks (nested, dec_and_lock, etc)
separately.

Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Larry Woodman <lwoodman@redhat.com>
Acked-by: Larry Woodman <lwoodman@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 31 insertions, 21 deletions

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 80cd162a8aa6..5f981be61416 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -113,6 +113,16 @@ static inline void vma_unlock_anon_vma(struct vm_area_struct *vma)
                 spin_unlock(&anon_vma->lock);
 }
 
+static inline void anon_vma_lock(struct anon_vma *anon_vma)
+{
+        spin_lock(&anon_vma->lock);
+}
+
+static inline void anon_vma_unlock(struct anon_vma *anon_vma)
+{
+        spin_unlock(&anon_vma->lock);
+}
+
 /*
  * anon_vma helper functions.
  */
diff --git a/mm/ksm.c b/mm/ksm.c
index 6c3e99b4ae7c..eb9f6806ed51 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -327,7 +327,7 @@ static void drop_anon_vma(struct rmap_item *rmap_item)
 
         if (atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->lock)) {
                 int empty = list_empty(&anon_vma->head);
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
                 if (empty)
                         anon_vma_free(anon_vma);
         }
@@ -1566,7 +1566,7 @@ again:
                 struct anon_vma_chain *vmac;
                 struct vm_area_struct *vma;
 
-                spin_lock(&anon_vma->lock);
+                anon_vma_lock(anon_vma);
                 list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) {
                         vma = vmac->vma;
                         if (rmap_item->address < vma->vm_start ||
@@ -1589,7 +1589,7 @@ again:
                         if (!search_new_forks || !mapcount)
                                 break;
                 }
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
                 if (!mapcount)
                         goto out;
         }
@@ -1619,7 +1619,7 @@ again:
                 struct anon_vma_chain *vmac;
                 struct vm_area_struct *vma;
 
-                spin_lock(&anon_vma->lock);
+                anon_vma_lock(anon_vma);
                 list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) {
                         vma = vmac->vma;
                         if (rmap_item->address < vma->vm_start ||
@@ -1637,11 +1637,11 @@ again:
                         ret = try_to_unmap_one(page, vma,
                                         rmap_item->address, flags);
                         if (ret != SWAP_AGAIN || !page_mapped(page)) {
-                                spin_unlock(&anon_vma->lock);
+                                anon_vma_unlock(anon_vma);
                                 goto out;
                         }
                 }
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
         }
         if (!search_new_forks++)
                 goto again;
@@ -1671,7 +1671,7 @@ again:
                 struct anon_vma_chain *vmac;
                 struct vm_area_struct *vma;
 
-                spin_lock(&anon_vma->lock);
+                anon_vma_lock(anon_vma);
                 list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) {
                         vma = vmac->vma;
                         if (rmap_item->address < vma->vm_start ||
@@ -1688,11 +1688,11 @@ again:
 
                         ret = rmap_one(page, vma, rmap_item->address, arg);
                         if (ret != SWAP_AGAIN) {
-                                spin_unlock(&anon_vma->lock);
+                                anon_vma_unlock(anon_vma);
                                 goto out;
                         }
                 }
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
         }
         if (!search_new_forks++)
                 goto again;
diff --git a/mm/migrate.c b/mm/migrate.c
index 4205b1d6049e..1855f869917d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -684,7 +684,7 @@ rcu_unlock:
         /* Drop an anon_vma reference if we took one */
         if (anon_vma && atomic_dec_and_lock(&anon_vma->external_refcount, &anon_vma->lock)) {
                 int empty = list_empty(&anon_vma->head);
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
                 if (empty)
                         anon_vma_free(anon_vma);
         }
diff --git a/mm/mmap.c b/mm/mmap.c
index e26f1ea7c904..f5db18decc2e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2593,7 +2593,7 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma)
                 if (!__test_and_clear_bit(0, (unsigned long *)
                                           &anon_vma->head.next))
                         BUG();
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
         }
 }
 
diff --git a/mm/rmap.c b/mm/rmap.c
index 38a336e2eea1..b65f00d1707f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -134,7 +134,7 @@ int anon_vma_prepare(struct vm_area_struct *vma)
                         allocated = anon_vma;
                 }
 
-                spin_lock(&anon_vma->lock);
+                anon_vma_lock(anon_vma);
                 /* page_table_lock to protect against threads */
                 spin_lock(&mm->page_table_lock);
                 if (likely(!vma->anon_vma)) {
@@ -147,7 +147,7 @@ int anon_vma_prepare(struct vm_area_struct *vma)
                         avc = NULL;
                 }
                 spin_unlock(&mm->page_table_lock);
-                spin_unlock(&anon_vma->lock);
+                anon_vma_unlock(anon_vma);
 
                 if (unlikely(allocated))
                         anon_vma_free(allocated);
@@ -170,9 +170,9 @@ static void anon_vma_chain_link(struct vm_area_struct *vma,
         avc->anon_vma = anon_vma;
         list_add(&avc->same_vma, &vma->anon_vma_chain);
 
-        spin_lock(&anon_vma->lock);
+        anon_vma_lock(anon_vma);
         list_add_tail(&avc->same_anon_vma, &anon_vma->head);
-        spin_unlock(&anon_vma->lock);
+        anon_vma_unlock(anon_vma);
 }
 
 /*
@@ -246,12 +246,12 @@ static void anon_vma_unlink(struct anon_vma_chain *anon_vma_chain)
         if (!anon_vma)
                 return;
 
-        spin_lock(&anon_vma->lock);
+        anon_vma_lock(anon_vma);
         list_del(&anon_vma_chain->same_anon_vma);
 
         /* We must garbage collect the anon_vma if it's empty */
         empty = list_empty(&anon_vma->head) && !anonvma_external_refcount(anon_vma);
-        spin_unlock(&anon_vma->lock);
+        anon_vma_unlock(anon_vma);
 
         if (empty)
                 anon_vma_free(anon_vma);
@@ -302,7 +302,7 @@ struct anon_vma *page_lock_anon_vma(struct page *page)
                 goto out;
 
         anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
-        spin_lock(&anon_vma->lock);
+        anon_vma_lock(anon_vma);
         return anon_vma;
 out:
         rcu_read_unlock();
@@ -311,7 +311,7 @@ out:
 
 void page_unlock_anon_vma(struct anon_vma *anon_vma)
 {
-        spin_unlock(&anon_vma->lock);
+        anon_vma_unlock(anon_vma);
         rcu_read_unlock();
 }
 
@@ -1389,7 +1389,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
         anon_vma = page_anon_vma(page);
         if (!anon_vma)
                 return ret;
-        spin_lock(&anon_vma->lock);
+        anon_vma_lock(anon_vma);
         list_for_each_entry(avc, &anon_vma->head, same_anon_vma) {
                 struct vm_area_struct *vma = avc->vma;
                 unsigned long address = vma_address(page, vma);
@@ -1399,7 +1399,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
                 if (ret != SWAP_AGAIN)
                         break;
         }
-        spin_unlock(&anon_vma->lock);
+        anon_vma_unlock(anon_vma);
         return ret;
 }