1 files changed, 82 insertions, 93 deletions

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index fe47fbba995a..72698db958e7 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -247,7 +247,6 @@ struct zs_pool {
 	struct size_class **size_class;
 	struct kmem_cache *handle_cachep;
 
-	gfp_t flags;	/* allocation flags used when growing pool */
 	atomic_long_t pages_allocated;
 
 	struct zs_pool_stats stats;
@@ -295,10 +294,10 @@ static void destroy_handle_cache(struct zs_pool *pool)
 	kmem_cache_destroy(pool->handle_cachep);
 }
 
-static unsigned long alloc_handle(struct zs_pool *pool)
+static unsigned long alloc_handle(struct zs_pool *pool, gfp_t gfp)
 {
 	return (unsigned long)kmem_cache_alloc(pool->handle_cachep,
-		pool->flags & ~__GFP_HIGHMEM);
+			gfp & ~__GFP_HIGHMEM);
 }
 
 static void free_handle(struct zs_pool *pool, unsigned long handle)
@@ -324,7 +323,12 @@ static void *zs_zpool_create(const char *name, gfp_t gfp,
 			     const struct zpool_ops *zpool_ops,
 			     struct zpool *zpool)
 {
-	return zs_create_pool(name, gfp);
+	/*
+	 * Ignore global gfp flags: zs_malloc() may be invoked from
+	 * different contexts and its caller must provide a valid
+	 * gfp mask.
+	 */
+	return zs_create_pool(name);
 }
 
 static void zs_zpool_destroy(void *pool)
@@ -335,7 +339,7 @@ static void zs_zpool_destroy(void *pool)
 static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp,
 			unsigned long *handle)
 {
-	*handle = zs_malloc(pool, size);
+	*handle = zs_malloc(pool, size, gfp);
 	return *handle ? 0 : -1;
 }
 static void zs_zpool_free(void *pool, unsigned long handle)
@@ -413,26 +417,28 @@ static int is_last_page(struct page *page)
 	return PagePrivate2(page);
 }
 
-static void get_zspage_mapping(struct page *page, unsigned int *class_idx,
+static void get_zspage_mapping(struct page *first_page,
+				unsigned int *class_idx,
 				enum fullness_group *fullness)
 {
 	unsigned long m;
-	BUG_ON(!is_first_page(page));
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
-	m = (unsigned long)page->mapping;
+	m = (unsigned long)first_page->mapping;
 	*fullness = m & FULLNESS_MASK;
 	*class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK;
 }
 
-static void set_zspage_mapping(struct page *page, unsigned int class_idx,
+static void set_zspage_mapping(struct page *first_page,
+				unsigned int class_idx,
 				enum fullness_group fullness)
 {
 	unsigned long m;
-	BUG_ON(!is_first_page(page));
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
 	m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) |
 			(fullness & FULLNESS_MASK);
-	page->mapping = (struct address_space *)m;
+	first_page->mapping = (struct address_space *)m;
 }
 
 /*
@@ -567,17 +573,17 @@ static const struct file_operations zs_stat_size_ops = {
 	.release        = single_release,
 };
 
-static int zs_pool_stat_create(const char *name, struct zs_pool *pool)
+static void zs_pool_stat_create(struct zs_pool *pool, const char *name)
 {
 	struct dentry *entry;
 
 	if (!zs_stat_root)
-		return -ENODEV;
+		return;
 
 	entry = debugfs_create_dir(name, zs_stat_root);
 	if (!entry) {
 		pr_warn("debugfs dir <%s> creation failed\n", name);
-		return -ENOMEM;
+		return;
 	}
 	pool->stat_dentry = entry;
 
@@ -586,10 +592,8 @@ static int zs_pool_stat_create(const char *name, struct zs_pool *pool)
 	if (!entry) {
 		pr_warn("%s: debugfs file entry <%s> creation failed\n",
 				name, "classes");
-		return -ENOMEM;
+		return;
 	}
-
-	return 0;
 }
 
 static void zs_pool_stat_destroy(struct zs_pool *pool)
@@ -607,9 +611,8 @@ static void __exit zs_stat_exit(void)
 {
 }
 
-static inline int zs_pool_stat_create(const char *name, struct zs_pool *pool)
+static inline void zs_pool_stat_create(struct zs_pool *pool, const char *name)
 {
-	return 0;
 }
 
 static inline void zs_pool_stat_destroy(struct zs_pool *pool)
@@ -617,7 +620,6 @@ static inline void zs_pool_stat_destroy(struct zs_pool *pool)
 }
 #endif
 
-
 /*
  * For each size class, zspages are divided into different groups
  * depending on how "full" they are. This was done so that we could
@@ -625,14 +627,15 @@ static inline void zs_pool_stat_destroy(struct zs_pool *pool)
  * the pool (not yet implemented). This function returns fullness
  * status of the given page.
  */
-static enum fullness_group get_fullness_group(struct page *page)
+static enum fullness_group get_fullness_group(struct page *first_page)
 {
 	int inuse, max_objects;
 	enum fullness_group fg;
-	BUG_ON(!is_first_page(page));
 
-	inuse = page->inuse;
-	max_objects = page->objects;
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
+
+	inuse = first_page->inuse;
+	max_objects = first_page->objects;
 
 	if (inuse == 0)
 		fg = ZS_EMPTY;
@@ -652,12 +655,13 @@ static enum fullness_group get_fullness_group(struct page *page)
  * have. This functions inserts the given zspage into the freelist
  * identified by <class, fullness_group>.
  */
-static void insert_zspage(struct page *page, struct size_class *class,
-				enum fullness_group fullness)
+static void insert_zspage(struct size_class *class,
+				enum fullness_group fullness,
+				struct page *first_page)
 {
 	struct page **head;
 
-	BUG_ON(!is_first_page(page));
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
 	if (fullness >= _ZS_NR_FULLNESS_GROUPS)
 		return;
@@ -667,7 +671,7 @@ static void insert_zspage(struct page *page, struct size_class *class,
 
 	head = &class->fullness_list[fullness];
 	if (!*head) {
-		*head = page;
+		*head = first_page;
 		return;
 	}
 
@@ -675,34 +679,35 @@ static void insert_zspage(struct page *page, struct size_class *class,
 	 * We want to see more ZS_FULL pages and less almost
 	 * empty/full. Put pages with higher ->inuse first.
 	 */
-	list_add_tail(&page->lru, &(*head)->lru);
-	if (page->inuse >= (*head)->inuse)
-		*head = page;
+	list_add_tail(&first_page->lru, &(*head)->lru);
+	if (first_page->inuse >= (*head)->inuse)
+		*head = first_page;
 }
 
 /*
  * This function removes the given zspage from the freelist identified
  * by <class, fullness_group>.
  */
-static void remove_zspage(struct page *page, struct size_class *class,
-				enum fullness_group fullness)
+static void remove_zspage(struct size_class *class,
+				enum fullness_group fullness,
+				struct page *first_page)
 {
 	struct page **head;
 
-	BUG_ON(!is_first_page(page));
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
 	if (fullness >= _ZS_NR_FULLNESS_GROUPS)
 		return;
 
 	head = &class->fullness_list[fullness];
-	BUG_ON(!*head);
+	VM_BUG_ON_PAGE(!*head, first_page);
 	if (list_empty(&(*head)->lru))
 		*head = NULL;
-	else if (*head == page)
+	else if (*head == first_page)
 		*head = (struct page *)list_entry((*head)->lru.next,
 					struct page, lru);
 
-	list_del_init(&page->lru);
+	list_del_init(&first_page->lru);
 	zs_stat_dec(class, fullness == ZS_ALMOST_EMPTY ?
 			CLASS_ALMOST_EMPTY : CLASS_ALMOST_FULL, 1);
 }
@@ -717,21 +722,19 @@ static void remove_zspage(struct page *page, struct size_class *class,
  * fullness group.
  */
 static enum fullness_group fix_fullness_group(struct size_class *class,
-						struct page *page)
+						struct page *first_page)
 {
 	int class_idx;
 	enum fullness_group currfg, newfg;
 
-	BUG_ON(!is_first_page(page));
-
-	get_zspage_mapping(page, &class_idx, &currfg);
-	newfg = get_fullness_group(page);
+	get_zspage_mapping(first_page, &class_idx, &currfg);
+	newfg = get_fullness_group(first_page);
 	if (newfg == currfg)
 		goto out;
 
-	remove_zspage(page, class, currfg);
-	insert_zspage(page, class, newfg);
-	set_zspage_mapping(page, class_idx, newfg);
+	remove_zspage(class, currfg, first_page);
+	insert_zspage(class, newfg, first_page);
+	set_zspage_mapping(first_page, class_idx, newfg);
 
 out:
 	return newfg;
@@ -809,7 +812,7 @@ static void *location_to_obj(struct page *page, unsigned long obj_idx)
 	unsigned long obj;
 
 	if (!page) {
-		BUG_ON(obj_idx);
+		VM_BUG_ON(obj_idx);
 		return NULL;
 	}
 
@@ -842,7 +845,7 @@ static unsigned long obj_to_head(struct size_class *class, struct page *page,
 			void *obj)
 {
 	if (class->huge) {
-		VM_BUG_ON(!is_first_page(page));
+		VM_BUG_ON_PAGE(!is_first_page(page), page);
 		return page_private(page);
 	} else
 		return *(unsigned long *)obj;
@@ -892,8 +895,8 @@ static void free_zspage(struct page *first_page)
 {
 	struct page *nextp, *tmp, *head_extra;
 
-	BUG_ON(!is_first_page(first_page));
-	BUG_ON(first_page->inuse);
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
+	VM_BUG_ON_PAGE(first_page->inuse, first_page);
 
 	head_extra = (struct page *)page_private(first_page);
 
@@ -914,12 +917,13 @@ static void free_zspage(struct page *first_page)
 }
 
 /* Initialize a newly allocated zspage */
-static void init_zspage(struct page *first_page, struct size_class *class)
+static void init_zspage(struct size_class *class, struct page *first_page)
 {
 	unsigned long off = 0;
 	struct page *page = first_page;
 
-	BUG_ON(!is_first_page(first_page));
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
+
 	while (page) {
 		struct page *next_page;
 		struct link_free *link;
@@ -1001,7 +1005,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags)
 		prev_page = page;
 	}
 
-	init_zspage(first_page, class);
+	init_zspage(class, first_page);
 
 	first_page->freelist = location_to_obj(first_page, 0);
 	/* Maximum number of objects we can store in this zspage */
@@ -1234,11 +1238,11 @@ static bool can_merge(struct size_class *prev, int size, int pages_per_zspage)
 	return true;
 }
 
-static bool zspage_full(struct page *page)
+static bool zspage_full(struct page *first_page)
 {
-	BUG_ON(!is_first_page(page));
+	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
-	return page->inuse == page->objects;
+	return first_page->inuse == first_page->objects;
 }
 
 unsigned long zs_get_total_pages(struct zs_pool *pool)
@@ -1274,14 +1278,12 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
 	struct page *pages[2];
 	void *ret;
 
-	BUG_ON(!handle);
-
 	/*
 	 * Because we use per-cpu mapping areas shared among the
 	 * pools/users, we can't allow mapping in interrupt context
 	 * because it can corrupt another users mappings.
 	 */
-	BUG_ON(in_interrupt());
+	WARN_ON_ONCE(in_interrupt());
 
 	/* From now on, migration cannot move the object */
 	pin_tag(handle);
@@ -1325,8 +1327,6 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
 	struct size_class *class;
 	struct mapping_area *area;
 
-	BUG_ON(!handle);
-
 	obj = handle_to_obj(handle);
 	obj_to_location(obj, &page, &obj_idx);
 	get_zspage_mapping(get_first_page(page), &class_idx, &fg);
@@ -1350,8 +1350,8 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
 }
 EXPORT_SYMBOL_GPL(zs_unmap_object);
 
-static unsigned long obj_malloc(struct page *first_page,
-		struct size_class *class, unsigned long handle)
+static unsigned long obj_malloc(struct size_class *class,
+				struct page *first_page, unsigned long handle)
 {
 	unsigned long obj;
 	struct link_free *link;
@@ -1391,7 +1391,7 @@ static unsigned long obj_malloc(struct page *first_page,
  * otherwise 0.
  * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail.
  */
-unsigned long zs_malloc(struct zs_pool *pool, size_t size)
+unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp)
 {
 	unsigned long handle, obj;
 	struct size_class *class;
@@ -1400,7 +1400,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
 	if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE))
 		return 0;
 
-	handle = alloc_handle(pool);
+	handle = alloc_handle(pool, gfp);
 	if (!handle)
 		return 0;
 
@@ -1413,7 +1413,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
 
 	if (!first_page) {
 		spin_unlock(&class->lock);
-		first_page = alloc_zspage(class, pool->flags);
+		first_page = alloc_zspage(class, gfp);
 		if (unlikely(!first_page)) {
 			free_handle(pool, handle);
 			return 0;
@@ -1428,7 +1428,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
 				class->size, class->pages_per_zspage));
 	}
 
-	obj = obj_malloc(first_page, class, handle);
+	obj = obj_malloc(class, first_page, handle);
 	/* Now move the zspage to another fullness group, if required */
 	fix_fullness_group(class, first_page);
 	record_obj(handle, obj);
@@ -1438,16 +1438,13 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
 }
 EXPORT_SYMBOL_GPL(zs_malloc);
 
-static void obj_free(struct zs_pool *pool, struct size_class *class,
-			unsigned long obj)
+static void obj_free(struct size_class *class, unsigned long obj)
 {
 	struct link_free *link;
 	struct page *first_page, *f_page;
 	unsigned long f_objidx, f_offset;
 	void *vaddr;
 
-	BUG_ON(!obj);
-
 	obj &= ~OBJ_ALLOCATED_TAG;
 	obj_to_location(obj, &f_page, &f_objidx);
 	first_page = get_first_page(f_page);
@@ -1487,7 +1484,7 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
 	class = pool->size_class[class_idx];
 
 	spin_lock(&class->lock);
-	obj_free(pool, class, obj);
+	obj_free(class, obj);
 	fullness = fix_fullness_group(class, first_page);
 	if (fullness == ZS_EMPTY) {
 		zs_stat_dec(class, OBJ_ALLOCATED, get_maxobj_per_zspage(
@@ -1503,8 +1500,8 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
 }
 EXPORT_SYMBOL_GPL(zs_free);
 
-static void zs_object_copy(unsigned long dst, unsigned long src,
-				struct size_class *class)
+static void zs_object_copy(struct size_class *class, unsigned long dst,
+				unsigned long src)
 {
 	struct page *s_page, *d_page;
 	unsigned long s_objidx, d_objidx;
@@ -1547,7 +1544,6 @@ static void zs_object_copy(unsigned long dst, unsigned long src,
 			kunmap_atomic(d_addr);
 			kunmap_atomic(s_addr);
 			s_page = get_next_page(s_page);
-			BUG_ON(!s_page);
 			s_addr = kmap_atomic(s_page);
 			d_addr = kmap_atomic(d_page);
 			s_size = class->size - written;
@@ -1557,7 +1553,6 @@ static void zs_object_copy(unsigned long dst, unsigned long src,
 		if (d_off >= PAGE_SIZE) {
 			kunmap_atomic(d_addr);
 			d_page = get_next_page(d_page);
-			BUG_ON(!d_page);
 			d_addr = kmap_atomic(d_page);
 			d_size = class->size - written;
 			d_off = 0;
@@ -1572,8 +1567,8 @@ static void zs_object_copy(unsigned long dst, unsigned long src,
  * Find alloced object in zspage from index object and
  * return handle.
  */
-static unsigned long find_alloced_obj(struct page *page, int index,
-					struct size_class *class)
+static unsigned long find_alloced_obj(struct size_class *class,
+					struct page *page, int index)
 {
 	unsigned long head;
 	int offset = 0;
@@ -1623,7 +1618,7 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
 	int ret = 0;
 
 	while (1) {
-		handle = find_alloced_obj(s_page, index, class);
+		handle = find_alloced_obj(class, s_page, index);
 		if (!handle) {
 			s_page = get_next_page(s_page);
 			if (!s_page)
@@ -1640,8 +1635,8 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
 		}
 
 		used_obj = handle_to_obj(handle);
-		free_obj = obj_malloc(d_page, class, handle);
-		zs_object_copy(free_obj, used_obj, class);
+		free_obj = obj_malloc(class, d_page, handle);
+		zs_object_copy(class, free_obj, used_obj);
 		index++;
 		/*
 		 * record_obj updates handle's value to free_obj and it will
@@ -1652,7 +1647,7 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
 		free_obj |= BIT(HANDLE_PIN_BIT);
 		record_obj(handle, free_obj);
 		unpin_tag(handle);
-		obj_free(pool, class, used_obj);
+		obj_free(class, used_obj);
 	}
 
 	/* Remember last position in this iteration */
@@ -1670,7 +1665,7 @@ static struct page *isolate_target_page(struct size_class *class)
 	for (i = 0; i < _ZS_NR_FULLNESS_GROUPS; i++) {
 		page = class->fullness_list[i];
 		if (page) {
-			remove_zspage(page, class, i);
+			remove_zspage(class, i, page);
 			break;
 		}
 	}
@@ -1692,10 +1687,8 @@ static enum fullness_group putback_zspage(struct zs_pool *pool,
 {
 	enum fullness_group fullness;
 
-	BUG_ON(!is_first_page(first_page));
-
 	fullness = get_fullness_group(first_page);
-	insert_zspage(first_page, class, fullness);
+	insert_zspage(class, fullness, first_page);
 	set_zspage_mapping(first_page, class->index, fullness);
 
 	if (fullness == ZS_EMPTY) {
@@ -1720,7 +1713,7 @@ static struct page *isolate_source_page(struct size_class *class)
 		if (!page)
 			continue;
 
-		remove_zspage(page, class, i);
+		remove_zspage(class, i, page);
 		break;
 	}
 
@@ -1757,8 +1750,6 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class)
 	spin_lock(&class->lock);
 	while ((src_page = isolate_source_page(class))) {
 
-		BUG_ON(!is_first_page(src_page));
-
 		if (!zs_can_compact(class))
 			break;
 
@@ -1887,7 +1878,7 @@ static int zs_register_shrinker(struct zs_pool *pool)
  * On success, a pointer to the newly created pool is returned,
  * otherwise NULL.
  */
-struct zs_pool *zs_create_pool(const char *name, gfp_t flags)
+struct zs_pool *zs_create_pool(const char *name)
 {
 	int i;
 	struct zs_pool *pool;
@@ -1957,10 +1948,8 @@ struct zs_pool *zs_create_pool(const char *name, gfp_t flags)
 		prev_class = class;
 	}
 
-	pool->flags = flags;
-
-	if (zs_pool_stat_create(name, pool))
-		goto err;
+	/* debug only, don't abort if it fails */
+	zs_pool_stat_create(pool, name);
 
 	/*
 	 * Not critical, we still can use the pool