79 static inline struct anon_vma *anon_vma_alloc(void)  in anon_vma_alloc()
81 	struct anon_vma *anon_vma;  in anon_vma_alloc()  local
83 	anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);  in anon_vma_alloc()
84 	if (anon_vma) {  in anon_vma_alloc()
85 		atomic_set(&anon_vma->refcount, 1);  in anon_vma_alloc()
86 		anon_vma->degree = 1;	/* Reference for first vma */  in anon_vma_alloc()
87 		anon_vma->parent = anon_vma;  in anon_vma_alloc()
92 		anon_vma->root = anon_vma;  in anon_vma_alloc()
95 	return anon_vma;  in anon_vma_alloc()
98 static inline void anon_vma_free(struct anon_vma *anon_vma)  in anon_vma_free()  argument
100 	VM_BUG_ON(atomic_read(&anon_vma->refcount));  in anon_vma_free()
120 	if (rwsem_is_locked(&anon_vma->root->rwsem)) {  in anon_vma_free()
121 		anon_vma_lock_write(anon_vma);  in anon_vma_free()
122 		anon_vma_unlock_write(anon_vma);  in anon_vma_free()
125 	kmem_cache_free(anon_vma_cachep, anon_vma);  in anon_vma_free()
140 				struct anon_vma *anon_vma)  in anon_vma_chain_link()  argument
143 	avc->anon_vma = anon_vma;  in anon_vma_chain_link()
145 	anon_vma_interval_tree_insert(avc, &anon_vma->rb_root);  in anon_vma_chain_link()
179 	struct anon_vma *anon_vma, *allocated;  in __anon_vma_prepare()  local
188 	anon_vma = find_mergeable_anon_vma(vma);  in __anon_vma_prepare()
190 	if (!anon_vma) {  in __anon_vma_prepare()
191 		anon_vma = anon_vma_alloc();  in __anon_vma_prepare()
192 		if (unlikely(!anon_vma))  in __anon_vma_prepare()
194 		allocated = anon_vma;  in __anon_vma_prepare()
197 	anon_vma_lock_write(anon_vma);  in __anon_vma_prepare()
200 	if (likely(!vma->anon_vma)) {  in __anon_vma_prepare()
201 		vma->anon_vma = anon_vma;  in __anon_vma_prepare()
202 		anon_vma_chain_link(vma, avc, anon_vma);  in __anon_vma_prepare()
204 		anon_vma->degree++;  in __anon_vma_prepare()
209 	anon_vma_unlock_write(anon_vma);  in __anon_vma_prepare()
232 static inline struct anon_vma *lock_anon_vma_root(struct anon_vma *root, struct anon_vma *anon_vma)  in lock_anon_vma_root()  argument
234 	struct anon_vma *new_root = anon_vma->root;  in lock_anon_vma_root()
244 static inline void unlock_anon_vma_root(struct anon_vma *root)  in unlock_anon_vma_root()
265 	struct anon_vma *root = NULL;  in anon_vma_clone()
268 		struct anon_vma *anon_vma;  in anon_vma_clone()  local
278 		anon_vma = pavc->anon_vma;  in anon_vma_clone()
279 		root = lock_anon_vma_root(root, anon_vma);  in anon_vma_clone()
280 		anon_vma_chain_link(dst, avc, anon_vma);  in anon_vma_clone()
290 		if (!dst->anon_vma && anon_vma != src->anon_vma &&  in anon_vma_clone()
291 				anon_vma->degree < 2)  in anon_vma_clone()
292 			dst->anon_vma = anon_vma;  in anon_vma_clone()
294 	if (dst->anon_vma)  in anon_vma_clone()
295 		dst->anon_vma->degree++;  in anon_vma_clone()
306 	dst->anon_vma = NULL;  in anon_vma_clone()
319 	struct anon_vma *anon_vma;  in anon_vma_fork()  local
323 	if (!pvma->anon_vma)  in anon_vma_fork()
327 	vma->anon_vma = NULL;  in anon_vma_fork()
338 	if (vma->anon_vma)  in anon_vma_fork()
342 	anon_vma = anon_vma_alloc();  in anon_vma_fork()
343 	if (!anon_vma)  in anon_vma_fork()
353 	anon_vma->root = pvma->anon_vma->root;  in anon_vma_fork()
354 	anon_vma->parent = pvma->anon_vma;  in anon_vma_fork()
360 	get_anon_vma(anon_vma->root);  in anon_vma_fork()
362 	vma->anon_vma = anon_vma;  in anon_vma_fork()
363 	anon_vma_lock_write(anon_vma);  in anon_vma_fork()
364 	anon_vma_chain_link(vma, avc, anon_vma);  in anon_vma_fork()
365 	anon_vma->parent->degree++;  in anon_vma_fork()
366 	anon_vma_unlock_write(anon_vma);  in anon_vma_fork()
371 	put_anon_vma(anon_vma);  in anon_vma_fork()
380 	struct anon_vma *root = NULL;  in unlink_anon_vmas()
387 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
389 		root = lock_anon_vma_root(root, anon_vma);  in unlink_anon_vmas()
390 		anon_vma_interval_tree_remove(avc, &anon_vma->rb_root);  in unlink_anon_vmas()
396 		if (RB_EMPTY_ROOT(&anon_vma->rb_root.rb_root)) {  in unlink_anon_vmas()
397 			anon_vma->parent->degree--;  in unlink_anon_vmas()
404 	if (vma->anon_vma)  in unlink_anon_vmas()
405 		vma->anon_vma->degree--;  in unlink_anon_vmas()
414 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
416 		VM_WARN_ON(anon_vma->degree);  in unlink_anon_vmas()
417 		put_anon_vma(anon_vma);  in unlink_anon_vmas()
426 	struct anon_vma *anon_vma = data;  in anon_vma_ctor()  local
428 	init_rwsem(&anon_vma->rwsem);  in anon_vma_ctor()
429 	atomic_set(&anon_vma->refcount, 0);  in anon_vma_ctor()
430 	anon_vma->rb_root = RB_ROOT_CACHED;  in anon_vma_ctor()
435 	anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),  in anon_vma_init()
465 struct anon_vma *page_get_anon_vma(struct page *page)  in page_get_anon_vma()
467 	struct anon_vma *anon_vma = NULL;  in page_get_anon_vma()  local
477 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in page_get_anon_vma()
478 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in page_get_anon_vma()
479 		anon_vma = NULL;  in page_get_anon_vma()
492 		put_anon_vma(anon_vma);  in page_get_anon_vma()
498 	return anon_vma;  in page_get_anon_vma()
508 struct anon_vma *page_lock_anon_vma_read(struct page *page)  in page_lock_anon_vma_read()
510 	struct anon_vma *anon_vma = NULL;  in page_lock_anon_vma_read()  local
511 	struct anon_vma *root_anon_vma;  in page_lock_anon_vma_read()
521 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in page_lock_anon_vma_read()
522 	root_anon_vma = READ_ONCE(anon_vma->root);  in page_lock_anon_vma_read()
531 			anon_vma = NULL;  in page_lock_anon_vma_read()
537 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in page_lock_anon_vma_read()
538 		anon_vma = NULL;  in page_lock_anon_vma_read()
544 		put_anon_vma(anon_vma);  in page_lock_anon_vma_read()
550 	anon_vma_lock_read(anon_vma);  in page_lock_anon_vma_read()
552 	if (atomic_dec_and_test(&anon_vma->refcount)) {  in page_lock_anon_vma_read()
558 		anon_vma_unlock_read(anon_vma);  in page_lock_anon_vma_read()
559 		__put_anon_vma(anon_vma);  in page_lock_anon_vma_read()
560 		anon_vma = NULL;  in page_lock_anon_vma_read()
563 	return anon_vma;  in page_lock_anon_vma_read()
567 	return anon_vma;  in page_lock_anon_vma_read()
570 void page_unlock_anon_vma_read(struct anon_vma *anon_vma)  in page_unlock_anon_vma_read()  argument
572 	anon_vma_unlock_read(anon_vma);  in page_unlock_anon_vma_read()
692 		struct anon_vma *page__anon_vma = page_anon_vma(page);  in page_address_in_vma()
697 		if (!vma->anon_vma || !page__anon_vma ||  in page_address_in_vma()
698 		    vma->anon_vma->root != page__anon_vma->root)  in page_address_in_vma()
1003 	struct anon_vma *anon_vma = vma->anon_vma;  in page_move_anon_rmap()  local
1008 	VM_BUG_ON_VMA(!anon_vma, vma);  in page_move_anon_rmap()
1010 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in page_move_anon_rmap()
1016 	WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);  in page_move_anon_rmap()
1029 	struct anon_vma *anon_vma = vma->anon_vma;  in __page_set_anon_rmap()  local
1031 	BUG_ON(!anon_vma);  in __page_set_anon_rmap()
1042 		anon_vma = anon_vma->root;  in __page_set_anon_rmap()
1044 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in __page_set_anon_rmap()
1045 	page->mapping = (struct address_space *) anon_vma;  in __page_set_anon_rmap()
1071 	BUG_ON(page_anon_vma(page)->root != vma->anon_vma->root);  in __page_check_anon_rmap()
1767 void __put_anon_vma(struct anon_vma *anon_vma)  in __put_anon_vma()  argument
1769 	struct anon_vma *root = anon_vma->root;  in __put_anon_vma()
1771 	anon_vma_free(anon_vma);  in __put_anon_vma()
1772 	if (root != anon_vma && atomic_dec_and_test(&root->refcount))  in __put_anon_vma()
1776 static struct anon_vma *rmap_walk_anon_lock(struct page *page,  in rmap_walk_anon_lock()
1779 	struct anon_vma *anon_vma;  in rmap_walk_anon_lock()  local
1790 	anon_vma = page_anon_vma(page);  in rmap_walk_anon_lock()
1791 	if (!anon_vma)  in rmap_walk_anon_lock()
1794 	anon_vma_lock_read(anon_vma);  in rmap_walk_anon_lock()
1795 	return anon_vma;  in rmap_walk_anon_lock()
1815 	struct anon_vma *anon_vma;  in rmap_walk_anon()  local
1820 		anon_vma = page_anon_vma(page);  in rmap_walk_anon()
1822 		VM_BUG_ON_PAGE(!anon_vma, page);  in rmap_walk_anon()
1824 		anon_vma = rmap_walk_anon_lock(page, rwc);  in rmap_walk_anon()
1826 	if (!anon_vma)  in rmap_walk_anon()
1831 	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root,  in rmap_walk_anon()
1848 		anon_vma_unlock_read(anon_vma);  in rmap_walk_anon()
1936 	struct anon_vma *anon_vma = vma->anon_vma;  in hugepage_add_anon_rmap()  local
1940 	BUG_ON(!anon_vma);  in hugepage_add_anon_rmap()