85 static inline struct anon_vma *anon_vma_alloc(void)  in anon_vma_alloc()
87 	struct anon_vma *anon_vma;  in anon_vma_alloc()  local
89 	anon_vma = kmem_cache_alloc(anon_vma_cachep, GFP_KERNEL);  in anon_vma_alloc()
90 	if (anon_vma) {  in anon_vma_alloc()
91 		atomic_set(&anon_vma->refcount, 1);  in anon_vma_alloc()
92 		anon_vma->degree = 1;	/* Reference for first vma */  in anon_vma_alloc()
93 		anon_vma->parent = anon_vma;  in anon_vma_alloc()
98 		anon_vma->root = anon_vma;  in anon_vma_alloc()
101 	return anon_vma;  in anon_vma_alloc()
104 static inline void anon_vma_free(struct anon_vma *anon_vma)  in anon_vma_free()  argument
106 	VM_BUG_ON(atomic_read(&anon_vma->refcount));  in anon_vma_free()
126 	if (rwsem_is_locked(&anon_vma->root->rwsem)) {  in anon_vma_free()
127 		anon_vma_lock_write(anon_vma);  in anon_vma_free()
128 		anon_vma_unlock_write(anon_vma);  in anon_vma_free()
131 	kmem_cache_free(anon_vma_cachep, anon_vma);  in anon_vma_free()
146 				struct anon_vma *anon_vma)  in anon_vma_chain_link()  argument
149 	avc->anon_vma = anon_vma;  in anon_vma_chain_link()
151 	anon_vma_interval_tree_insert(avc, &anon_vma->rb_root);  in anon_vma_chain_link()
185 	struct anon_vma *anon_vma, *allocated;  in __anon_vma_prepare()  local
194 	anon_vma = find_mergeable_anon_vma(vma);  in __anon_vma_prepare()
196 	if (!anon_vma) {  in __anon_vma_prepare()
197 		anon_vma = anon_vma_alloc();  in __anon_vma_prepare()
198 		if (unlikely(!anon_vma))  in __anon_vma_prepare()
200 		allocated = anon_vma;  in __anon_vma_prepare()
203 	anon_vma_lock_write(anon_vma);  in __anon_vma_prepare()
206 	if (likely(!vma->anon_vma)) {  in __anon_vma_prepare()
207 		vma->anon_vma = anon_vma;  in __anon_vma_prepare()
208 		anon_vma_chain_link(vma, avc, anon_vma);  in __anon_vma_prepare()
210 		anon_vma->degree++;  in __anon_vma_prepare()
215 	anon_vma_unlock_write(anon_vma);  in __anon_vma_prepare()
238 static inline struct anon_vma *lock_anon_vma_root(struct anon_vma *root, struct anon_vma *anon_vma)  in lock_anon_vma_root()  argument
240 	struct anon_vma *new_root = anon_vma->root;  in lock_anon_vma_root()
250 static inline void unlock_anon_vma_root(struct anon_vma *root)  in unlock_anon_vma_root()
277 	struct anon_vma *root = NULL;  in anon_vma_clone()
280 		struct anon_vma *anon_vma;  in anon_vma_clone()  local
290 		anon_vma = pavc->anon_vma;  in anon_vma_clone()
291 		root = lock_anon_vma_root(root, anon_vma);  in anon_vma_clone()
292 		anon_vma_chain_link(dst, avc, anon_vma);  in anon_vma_clone()
302 		if (!dst->anon_vma && src->anon_vma &&  in anon_vma_clone()
303 		    anon_vma != src->anon_vma && anon_vma->degree < 2)  in anon_vma_clone()
304 			dst->anon_vma = anon_vma;  in anon_vma_clone()
306 	if (dst->anon_vma)  in anon_vma_clone()
307 		dst->anon_vma->degree++;  in anon_vma_clone()
318 	dst->anon_vma = NULL;  in anon_vma_clone()
331 	struct anon_vma *anon_vma;  in anon_vma_fork()  local
335 	if (!pvma->anon_vma)  in anon_vma_fork()
339 	vma->anon_vma = NULL;  in anon_vma_fork()
350 	if (vma->anon_vma)  in anon_vma_fork()
354 	anon_vma = anon_vma_alloc();  in anon_vma_fork()
355 	if (!anon_vma)  in anon_vma_fork()
365 	anon_vma->root = pvma->anon_vma->root;  in anon_vma_fork()
366 	anon_vma->parent = pvma->anon_vma;  in anon_vma_fork()
372 	get_anon_vma(anon_vma->root);  in anon_vma_fork()
374 	vma->anon_vma = anon_vma;  in anon_vma_fork()
375 	anon_vma_lock_write(anon_vma);  in anon_vma_fork()
376 	anon_vma_chain_link(vma, avc, anon_vma);  in anon_vma_fork()
377 	anon_vma->parent->degree++;  in anon_vma_fork()
378 	anon_vma_unlock_write(anon_vma);  in anon_vma_fork()
383 	put_anon_vma(anon_vma);  in anon_vma_fork()
392 	struct anon_vma *root = NULL;  in unlink_anon_vmas()
399 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
401 		root = lock_anon_vma_root(root, anon_vma);  in unlink_anon_vmas()
402 		anon_vma_interval_tree_remove(avc, &anon_vma->rb_root);  in unlink_anon_vmas()
408 		if (RB_EMPTY_ROOT(&anon_vma->rb_root.rb_root)) {  in unlink_anon_vmas()
409 			anon_vma->parent->degree--;  in unlink_anon_vmas()
416 	if (vma->anon_vma)  in unlink_anon_vmas()
417 		vma->anon_vma->degree--;  in unlink_anon_vmas()
426 		struct anon_vma *anon_vma = avc->anon_vma;  in unlink_anon_vmas()  local
428 		VM_WARN_ON(anon_vma->degree);  in unlink_anon_vmas()
429 		put_anon_vma(anon_vma);  in unlink_anon_vmas()
438 	struct anon_vma *anon_vma = data;  in anon_vma_ctor()  local
440 	init_rwsem(&anon_vma->rwsem);  in anon_vma_ctor()
441 	atomic_set(&anon_vma->refcount, 0);  in anon_vma_ctor()
442 	anon_vma->rb_root = RB_ROOT_CACHED;  in anon_vma_ctor()
447 	anon_vma_cachep = kmem_cache_create("anon_vma", sizeof(struct anon_vma),  in anon_vma_init()
478 struct anon_vma *page_get_anon_vma(struct page *page)  in page_get_anon_vma()
480 	struct anon_vma *anon_vma = NULL;  in page_get_anon_vma()  local
490 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in page_get_anon_vma()
491 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in page_get_anon_vma()
492 		anon_vma = NULL;  in page_get_anon_vma()
505 		put_anon_vma(anon_vma);  in page_get_anon_vma()
511 	return anon_vma;  in page_get_anon_vma()
521 struct anon_vma *page_lock_anon_vma_read(struct page *page)  in page_lock_anon_vma_read()
523 	struct anon_vma *anon_vma = NULL;  in page_lock_anon_vma_read()  local
524 	struct anon_vma *root_anon_vma;  in page_lock_anon_vma_read()
534 	anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);  in page_lock_anon_vma_read()
535 	root_anon_vma = READ_ONCE(anon_vma->root);  in page_lock_anon_vma_read()
544 			anon_vma = NULL;  in page_lock_anon_vma_read()
550 	if (!atomic_inc_not_zero(&anon_vma->refcount)) {  in page_lock_anon_vma_read()
551 		anon_vma = NULL;  in page_lock_anon_vma_read()
557 		put_anon_vma(anon_vma);  in page_lock_anon_vma_read()
563 	anon_vma_lock_read(anon_vma);  in page_lock_anon_vma_read()
565 	if (atomic_dec_and_test(&anon_vma->refcount)) {  in page_lock_anon_vma_read()
571 		anon_vma_unlock_read(anon_vma);  in page_lock_anon_vma_read()
572 		__put_anon_vma(anon_vma);  in page_lock_anon_vma_read()
573 		anon_vma = NULL;  in page_lock_anon_vma_read()
576 	return anon_vma;  in page_lock_anon_vma_read()
580 	return anon_vma;  in page_lock_anon_vma_read()
583 void page_unlock_anon_vma_read(struct anon_vma *anon_vma)  in page_unlock_anon_vma_read()  argument
585 	anon_vma_unlock_read(anon_vma);  in page_unlock_anon_vma_read()
705 		struct anon_vma *page__anon_vma = page_anon_vma(page);  in page_address_in_vma()
710 		if (!vma->anon_vma || !page__anon_vma ||  in page_address_in_vma()
711 		    vma->anon_vma->root != page__anon_vma->root)  in page_address_in_vma()
1016 	struct anon_vma *anon_vma = vma->anon_vma;  in page_move_anon_rmap()  local
1021 	VM_BUG_ON_VMA(!anon_vma, vma);  in page_move_anon_rmap()
1023 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in page_move_anon_rmap()
1029 	WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);  in page_move_anon_rmap()
1042 	struct anon_vma *anon_vma = vma->anon_vma;  in __page_set_anon_rmap()  local
1044 	BUG_ON(!anon_vma);  in __page_set_anon_rmap()
1055 		anon_vma = anon_vma->root;  in __page_set_anon_rmap()
1057 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;  in __page_set_anon_rmap()
1058 	page->mapping = (struct address_space *) anon_vma;  in __page_set_anon_rmap()
1083 	VM_BUG_ON_PAGE(page_anon_vma(page)->root != vma->anon_vma->root, page);  in __page_check_anon_rmap()
1802 void __put_anon_vma(struct anon_vma *anon_vma)  in __put_anon_vma()  argument
1804 	struct anon_vma *root = anon_vma->root;  in __put_anon_vma()
1806 	anon_vma_free(anon_vma);  in __put_anon_vma()
1807 	if (root != anon_vma && atomic_dec_and_test(&root->refcount))  in __put_anon_vma()
1811 static struct anon_vma *rmap_walk_anon_lock(struct page *page,  in rmap_walk_anon_lock()
1814 	struct anon_vma *anon_vma;  in rmap_walk_anon_lock()  local
1825 	anon_vma = page_anon_vma(page);  in rmap_walk_anon_lock()
1826 	if (!anon_vma)  in rmap_walk_anon_lock()
1829 	anon_vma_lock_read(anon_vma);  in rmap_walk_anon_lock()
1830 	return anon_vma;  in rmap_walk_anon_lock()
1850 	struct anon_vma *anon_vma;  in rmap_walk_anon()  local
1855 		anon_vma = page_anon_vma(page);  in rmap_walk_anon()
1857 		VM_BUG_ON_PAGE(!anon_vma, page);  in rmap_walk_anon()
1859 		anon_vma = rmap_walk_anon_lock(page, rwc);  in rmap_walk_anon()
1861 	if (!anon_vma)  in rmap_walk_anon()
1866 	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root,  in rmap_walk_anon()
1883 		anon_vma_unlock_read(anon_vma);  in rmap_walk_anon()
1971 	struct anon_vma *anon_vma = vma->anon_vma;  in hugepage_add_anon_rmap()  local
1975 	BUG_ON(!anon_vma);  in hugepage_add_anon_rmap()