1 files changed, 17 insertions, 47 deletions

diff --git a/mm/z3fold.c b/mm/z3fold.c
index b3c0577b8095..83b5a3514427 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -297,9 +297,6 @@ static inline void free_handle(unsigned long handle, struct z3fold_header *zhdr)
 	int i;
 	bool is_free;
 
-	if (handle & (1 << PAGE_HEADLESS))
-		return;
-
 	if (WARN_ON(*(unsigned long *)handle == 0))
 		return;
 
@@ -345,7 +342,7 @@ static struct file_system_type z3fold_fs = {
 };
 
 static struct vfsmount *z3fold_mnt;
-static int z3fold_mount(void)
+static int __init z3fold_mount(void)
 {
 	int ret = 0;
 
@@ -420,7 +417,6 @@ static void free_z3fold_page(struct page *page, bool headless)
 		__ClearPageMovable(page);
 		unlock_page(page);
 	}
-	ClearPagePrivate(page);
 	__free_page(page);
 }
 
@@ -521,6 +517,8 @@ static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked)
 	list_add(&zhdr->buddy, &pool->stale);
 	queue_work(pool->release_wq, &pool->work);
 	spin_unlock(&pool->stale_lock);
+
+	atomic64_dec(&pool->pages_nr);
 }
 
 static void release_z3fold_page(struct kref *ref)
@@ -738,13 +736,9 @@ static struct z3fold_header *compact_single_buddy(struct z3fold_header *zhdr)
 	return new_zhdr;
 
 out_fail:
-	if (new_zhdr) {
-		if (kref_put(&new_zhdr->refcount, release_z3fold_page_locked))
-			atomic64_dec(&pool->pages_nr);
-		else {
-			add_to_unbuddied(pool, new_zhdr);
-			z3fold_page_unlock(new_zhdr);
-		}
+	if (new_zhdr && !kref_put(&new_zhdr->refcount, release_z3fold_page_locked)) {
+		add_to_unbuddied(pool, new_zhdr);
+		z3fold_page_unlock(new_zhdr);
 	}
 	return NULL;
 
@@ -817,10 +811,8 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked)
 	list_del_init(&zhdr->buddy);
 	spin_unlock(&pool->lock);
 
-	if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) {
-		atomic64_dec(&pool->pages_nr);
+	if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
 		return;
-	}
 
 	if (test_bit(PAGE_STALE, &page->private) ||
 	    test_and_set_bit(PAGE_CLAIMED, &page->private)) {
@@ -830,9 +822,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked)
 
 	if (!zhdr->foreign_handles && buddy_single(zhdr) &&
 	    zhdr->mapped_count == 0 && compact_single_buddy(zhdr)) {
-		if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
-			atomic64_dec(&pool->pages_nr);
-		else {
+		if (!kref_put(&zhdr->refcount, release_z3fold_page_locked)) {
 			clear_bit(PAGE_CLAIMED, &page->private);
 			z3fold_page_unlock(zhdr);
 		}
@@ -877,7 +867,6 @@ lookup:
 
 		/* Re-check under lock. */
 		spin_lock(&pool->lock);
-		l = &unbuddied[i];
 		if (unlikely(zhdr != list_first_entry(READ_ONCE(l),
 						struct z3fold_header, buddy)) ||
 		    !z3fold_page_trylock(zhdr)) {
@@ -1064,9 +1053,6 @@ static void z3fold_destroy_pool(struct z3fold_pool *pool)
  * performed first. If no suitable free region is found, then a new page is
  * allocated and added to the pool to satisfy the request.
  *
- * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used
- * as z3fold pool pages.
- *
  * Return: 0 if success and handle is set, otherwise -EINVAL if the size or
  * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
  * a new page.
@@ -1094,10 +1080,8 @@ retry:
 		if (zhdr) {
 			bud = get_free_buddy(zhdr, chunks);
 			if (bud == HEADLESS) {
-				if (kref_put(&zhdr->refcount,
+				if (!kref_put(&zhdr->refcount,
 					     release_z3fold_page_locked))
-					atomic64_dec(&pool->pages_nr);
-				else
 					z3fold_page_unlock(zhdr);
 				pr_err("No free chunks in unbuddied\n");
 				WARN_ON(1);
@@ -1190,9 +1174,9 @@ headless:
  * @handle:	handle associated with the allocation returned by z3fold_alloc()
  *
  * In the case that the z3fold page in which the allocation resides is under
- * reclaim, as indicated by the PG_reclaim flag being set, this function
- * only sets the first|last_chunks to 0.  The page is actually freed
- * once both buddies are evicted (see z3fold_reclaim_page() below).
+ * reclaim, as indicated by the PAGE_CLAIMED flag being set, this function
+ * only sets the first|middle|last_chunks to 0.  The page is actually freed
+ * once all buddies are evicted (see z3fold_reclaim_page() below).
  */
 static void z3fold_free(struct z3fold_pool *pool, unsigned long handle)
 {
@@ -1244,13 +1228,11 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle)
 
 	if (!page_claimed)
 		free_handle(handle, zhdr);
-	if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) {
-		atomic64_dec(&pool->pages_nr);
+	if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list))
 		return;
-	}
 	if (page_claimed) {
 		/* the page has not been claimed by us */
-		z3fold_page_unlock(zhdr);
+		put_z3fold_header(zhdr);
 		return;
 	}
 	if (test_and_set_bit(NEEDS_COMPACTING, &page->private)) {
@@ -1259,9 +1241,6 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle)
 		return;
 	}
 	if (zhdr->cpu < 0 || !cpu_online(zhdr->cpu)) {
-		spin_lock(&pool->lock);
-		list_del_init(&zhdr->buddy);
-		spin_unlock(&pool->lock);
 		zhdr->cpu = -1;
 		kref_get(&zhdr->refcount);
 		clear_bit(PAGE_CLAIMED, &page->private);
@@ -1358,9 +1337,7 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
 				break;
 			}
 			if (!z3fold_page_trylock(zhdr)) {
-				if (kref_put(&zhdr->refcount,
-						release_z3fold_page))
-					atomic64_dec(&pool->pages_nr);
+				kref_put(&zhdr->refcount, release_z3fold_page);
 				zhdr = NULL;
 				continue; /* can't evict at this point */
 			}
@@ -1371,10 +1348,8 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries)
 			 */
 			if (zhdr->foreign_handles ||
 			    test_and_set_bit(PAGE_CLAIMED, &page->private)) {
-				if (kref_put(&zhdr->refcount,
+				if (!kref_put(&zhdr->refcount,
 						release_z3fold_page_locked))
-					atomic64_dec(&pool->pages_nr);
-				else
 					z3fold_page_unlock(zhdr);
 				zhdr = NULL;
 				continue; /* can't evict such page */
@@ -1452,7 +1427,6 @@ next:
 			if (kref_put(&zhdr->refcount,
 					release_z3fold_page_locked)) {
 				kmem_cache_free(pool->c_handle, slots);
-				atomic64_dec(&pool->pages_nr);
 				return 0;
 			}
 			/*
@@ -1638,7 +1612,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
 	INIT_LIST_HEAD(&new_zhdr->buddy);
 	new_mapping = page_mapping(page);
 	__ClearPageMovable(page);
-	ClearPagePrivate(page);
 
 	get_page(newpage);
 	z3fold_page_lock(new_zhdr);
@@ -1658,7 +1631,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa
 
 	queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work);
 
-	page_mapcount_reset(page);
 	clear_bit(PAGE_CLAIMED, &page->private);
 	put_page(page);
 	return 0;
@@ -1676,10 +1648,8 @@ static void z3fold_page_putback(struct page *page)
 	if (!list_empty(&zhdr->buddy))
 		list_del_init(&zhdr->buddy);
 	INIT_LIST_HEAD(&page->lru);
-	if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) {
-		atomic64_dec(&pool->pages_nr);
+	if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
 		return;
-	}
 	spin_lock(&pool->lock);
 	list_add(&page->lru, &pool->lru);
 	spin_unlock(&pool->lock);