89 static inline struct anon_vma *anon_vma_alloc(void)  in anon_vma_alloc()
91 	struct anon_vma *anon_vma;  in anon_vma_alloc()  local
93 	anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);  in anon_vma_alloc()
94 	if (anon_vma) {  in anon_vma_alloc()
95 		atomic_set(&anon_vma->refcount, 1);  in anon_vma_alloc()
96 		anon_vma->num_children = 0;  in anon_vma_alloc()
97 		anon_vma->num_active_vmas = 0;  in anon_vma_alloc()
98 		anon_vma->parent = anon_vma;  in anon_vma_alloc()
103 		anon_vma->root = anon_vma;  in anon_vma_alloc()
106 	return anon_vma;  in anon_vma_alloc()
109 static inline void anon_vma_free(struct anon_vma *anon_vma)  in anon_vma_free()  argument
111 	VM_BUG_ON(atomic_read(&anon_vma->refcount));  in anon_vma_free()
131 	if (rwsem_is_locked(&anon_vma->root->rwsem)) {  in anon_vma_free()
132 		anon_vma_lock_write(anon_vma);  in anon_vma_free()
133 		anon_vma_unlock_write(anon_vma);  in anon_vma_free()
136 	kmem_cache_free(anon_vma_cachep, anon_vma);  in anon_vma_free()
151 				struct anon_vma *anon_vma)  in anon_vma_chain_link()  argument
154 	avc->anon_vma = anon_vma;  in anon_vma_chain_link()
156 	anon_vma_interval_tree_insert(avc, &anon_vma->rb_root);  in anon_vma_chain_link()
190 	struct anon_vma *anon_vma, *allocated;  in __anon_vma_prepare()  local
199 	anon_vma = find_mergeable_anon_vma(vma);  in __anon_vma_prepare()
201 	if (!anon_vma) {  in __anon_vma_prepare()
202 		anon_vma = anon_vma_alloc();  in __anon_vma_prepare()
203 		if (unlikely(!anon_vma))  in __anon_vma_prepare()
205 		anon_vma->num_children++; /* self-parent link for new root */  in __anon_vma_prepare()
206 		allocated = anon_vma;  in __anon_vma_prepare()
209 	anon_vma_lock_write(anon_vma);  in __anon_vma_prepare()
212 	if (likely(!vma->anon_vma)) {  in __anon_vma_prepare()
213 		vma->anon_vma = anon_vma;  in __anon_vma_prepare()
214 		anon_vma_chain_link(vma, avc, anon_vma);  in __anon_vma_prepare()
215 		anon_vma->num_active_vmas++;  in __anon_vma_prepare()
220 	anon_vma_unlock_write(anon_vma);  in __anon_vma_prepare()
243 static inline struct anon_vma *lock_anon_vma_root(struct anon_vma *root, struct anon_vma *anon_vma)  in lock_anon_vma_root()  argument
245 	struct anon_vma *new_root = anon_vma->root;  in lock_anon_vma_root()
255 static inline void unlock_anon_vma_root(struct anon_vma *root)  in unlock_anon_vma_root()
282 	struct anon_vma *root = NULL;  in anon_vma_clone()
285 		struct anon_vma *anon_vma;  in anon_vma_clone()  local
295 		anon_vma = pavc->anon_vma;  in anon_vma_clone()
296 		root = lock_anon_vma_root(root, anon_vma);  in anon_vma_clone()
297 		anon_vma_chain_link(dst, avc, anon_vma);  in anon_vma_clone()
306 		if (!dst->anon_vma && src->anon_vma &&  in anon_vma_clone()
307 		    anon_vma->num_children < 2 &&  in anon_vma_clone()
308 		    anon_vma->num_active_vmas == 0)  in anon_vma_clone()
309 			dst->anon_vma = anon_vma;  in anon_vma_clone()
311 	if (dst->anon_vma)  in anon_vma_clone()
312 		dst->anon_vma->num_active_vmas++;  in anon_vma_clone()
323 	dst->anon_vma = NULL;  in anon_vma_clone()
336 	struct anon_vma *anon_vma;  in anon_vma_fork()  local
340 	if (!pvma->anon_vma)  in anon_vma_fork()
344 	vma->anon_vma = NULL;  in anon_vma_fork()
355 	if (vma->anon_vma)  in anon_vma_fork()
359 	anon_vma = anon_vma_alloc();  in anon_vma_fork()
360 	if (!anon_vma)  in anon_vma_fork()
362 	anon_vma->num_active_vmas++;  in anon_vma_fork()
371 	anon_vma->root = pvma->anon_vma->root;  in anon_vma_fork()
372 	anon_vma->parent = pvma->anon_vma;  in anon_vma_fork()
378 	get_anon_vma(anon_vma->root);  in anon_vma_fork()
380 	vma->anon_vma = anon_vma;  in anon_vma_fork()
381 	anon_vma_lock_write(anon_vma);  in anon_vma_fork()
382 	anon_vma_chain_link(vma, avc, anon_vma);  in anon_vma_fork()
383 	anon_vma->parent->num_children++;  in anon_vma_fork()
384 	anon_vma_unlock_write(anon_vma);  in anon_vma_fork()
389 	put_anon_vma(anon_vma);  in anon_vma_fork()
398 	struct anon_vma *root = NULL;  in unlink_anon_vmas()
405 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
407 		root = lock_anon_vma_root(root, anon_vma);  in unlink_anon_vmas()
408 		anon_vma_interval_tree_remove(avc, &anon_vma->rb_root);  in unlink_anon_vmas()
414 		if (RB_EMPTY_ROOT(&anon_vma->rb_root.rb_root)) {  in unlink_anon_vmas()
415 			anon_vma->parent->num_children--;  in unlink_anon_vmas()
422 	if (vma->anon_vma) {  in unlink_anon_vmas()
423 		vma->anon_vma->num_active_vmas--;  in unlink_anon_vmas()
429 		vma->anon_vma = NULL;  in unlink_anon_vmas()
439 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
441 		VM_WARN_ON(anon_vma->num_children);  in unlink_anon_vmas()
442 		VM_WARN_ON(anon_vma->num_active_vmas);  in unlink_anon_vmas()
443 		put_anon_vma(anon_vma);  in unlink_anon_vmas()
452 	struct anon_vma *anon_vma = data;  in anon_vma_ctor()  local
454 	init_rwsem(&anon_vma->rwsem);  in anon_vma_ctor()
455 	atomic_set(&anon_vma->refcount, 0);  in anon_vma_ctor()
456 	anon_vma->rb_root = RB_ROOT_CACHED;  in anon_vma_ctor()
461 	anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),  in anon_vma_init()
492 struct anon_vma *folio_get_anon_vma(struct folio *folio)  in folio_get_anon_vma()
494 	struct anon_vma *anon_vma = NULL;  in folio_get_anon_vma()  local
504 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in folio_get_anon_vma()
505 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in folio_get_anon_vma()
506 		anon_vma = NULL;  in folio_get_anon_vma()
519 		put_anon_vma(anon_vma);  in folio_get_anon_vma()
525 	return anon_vma;  in folio_get_anon_vma()
536 struct anon_vma *folio_lock_anon_vma_read(struct folio *folio,  in folio_lock_anon_vma_read()
539 	struct anon_vma *anon_vma = NULL;  in folio_lock_anon_vma_read()  local
540 	struct anon_vma *root_anon_vma;  in folio_lock_anon_vma_read()
550 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in folio_lock_anon_vma_read()
551 	root_anon_vma = READ_ONCE(anon_vma->root);  in folio_lock_anon_vma_read()
560 			anon_vma = NULL;  in folio_lock_anon_vma_read()
566 		anon_vma = NULL;  in folio_lock_anon_vma_read()
572 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in folio_lock_anon_vma_read()
573 		anon_vma = NULL;  in folio_lock_anon_vma_read()
579 		put_anon_vma(anon_vma);  in folio_lock_anon_vma_read()
585 	anon_vma_lock_read(anon_vma);  in folio_lock_anon_vma_read()
587 	if (atomic_dec_and_test(&anon_vma->refcount)) {  in folio_lock_anon_vma_read()
593 		anon_vma_unlock_read(anon_vma);  in folio_lock_anon_vma_read()
594 		__put_anon_vma(anon_vma);  in folio_lock_anon_vma_read()
595 		anon_vma = NULL;  in folio_lock_anon_vma_read()
598 	return anon_vma;  in folio_lock_anon_vma_read()
602 	return anon_vma;  in folio_lock_anon_vma_read()
751 		struct anon_vma *page__anon_vma = folio_anon_vma(folio);  in page_address_in_vma()
756 		if (!vma->anon_vma || !page__anon_vma ||  in page_address_in_vma()
757 		    vma->anon_vma->root != page__anon_vma->root)  in page_address_in_vma()
1100 	void *anon_vma = vma->anon_vma;  in page_move_anon_rmap()  local
1104 	VM_BUG_ON_VMA(!anon_vma, vma);  in page_move_anon_rmap()
1106 	anon_vma += PAGE_MAPPING_ANON;  in page_move_anon_rmap()
1112 	WRITE_ONCE(folio->mapping, anon_vma);  in page_move_anon_rmap()
1126 	struct anon_vma *anon_vma = vma->anon_vma;  in __page_set_anon_rmap()  local
1128 	BUG_ON(!anon_vma);  in __page_set_anon_rmap()
1139 		anon_vma = anon_vma->root;  in __page_set_anon_rmap()
1147 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in __page_set_anon_rmap()
1148 	WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);  in __page_set_anon_rmap()
1176 	VM_BUG_ON_FOLIO(folio_anon_vma(folio)->root != vma->anon_vma->root,  in __page_check_anon_rmap()
2371 void __put_anon_vma(struct anon_vma *anon_vma)  in __put_anon_vma()  argument
2373 	struct anon_vma *root = anon_vma->root;  in __put_anon_vma()
2375 	anon_vma_free(anon_vma);  in __put_anon_vma()
2376 	if (root != anon_vma && atomic_dec_and_test(&root->refcount))  in __put_anon_vma()
2380 static struct anon_vma *rmap_walk_anon_lock(struct folio *folio,  in rmap_walk_anon_lock()
2383 	struct anon_vma *anon_vma;  in rmap_walk_anon_lock()  local
2394 	anon_vma = folio_anon_vma(folio);  in rmap_walk_anon_lock()
2395 	if (!anon_vma)  in rmap_walk_anon_lock()
2398 	if (anon_vma_trylock_read(anon_vma))  in rmap_walk_anon_lock()
2402 		anon_vma = NULL;  in rmap_walk_anon_lock()
2407 	anon_vma_lock_read(anon_vma);  in rmap_walk_anon_lock()
2409 	return anon_vma;  in rmap_walk_anon_lock()
2424 	struct anon_vma *anon_vma;  in rmap_walk_anon()  local
2429 		anon_vma = folio_anon_vma(folio);  in rmap_walk_anon()
2431 		VM_BUG_ON_FOLIO(!anon_vma, folio);  in rmap_walk_anon()
2433 		anon_vma = rmap_walk_anon_lock(folio, rwc);  in rmap_walk_anon()
2435 	if (!anon_vma)  in rmap_walk_anon()
2440 	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root,  in rmap_walk_anon()
2458 		anon_vma_unlock_read(anon_vma);  in rmap_walk_anon()
2554 	struct anon_vma *anon_vma = vma->anon_vma;  in hugepage_add_anon_rmap()  local
2558 	BUG_ON(!anon_vma);  in hugepage_add_anon_rmap()