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>

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.
  */

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 @@ int page_referenced_ksm(struct page *page, struct mem_cgroup *memcg,
 		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 @@ int page_referenced_ksm(struct page *page, struct mem_cgroup *memcg,
 			if (!search_new_forks || !mapcount)
 				break;
 		}
-		spin_unlock(&anon_vma->lock);
+		anon_vma_unlock(anon_vma);
 		if (!mapcount)
 			goto out;
 	}
@@ -1619,7 +1619,7 @@ int try_to_unmap_ksm(struct page *page, enum ttu_flags flags)
 		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 @@ int try_to_unmap_ksm(struct page *page, enum ttu_flags flags)
 			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 @@ int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
 		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 @@ int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
 
 			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;

mm/migrate.c

@@ -684,7 +684,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 	/* 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);
 	}

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);
 	}
 }
 

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 @@ struct anon_vma *page_lock_anon_vma(struct page *page)
 
 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;
 }