27 static bool kernfs_active(struct kernfs_node *kn)  in kernfs_active()  argument
30 	return atomic_read(&kn->active) >= 0;  in kernfs_active()
33 static bool kernfs_lockdep(struct kernfs_node *kn)  in kernfs_lockdep()  argument
36 	return kn->flags & KERNFS_LOCKDEP;  in kernfs_lockdep()
42 static int kernfs_name_locked(struct kernfs_node *kn, char *buf, size_t buflen)  in kernfs_name_locked()  argument
44 	if (!kn)  in kernfs_name_locked()
47 	return strlcpy(buf, kn->parent ? kn->name : "/", buflen);  in kernfs_name_locked()
71 	da = kernfs_depth(ra->kn, a);  in kernfs_common_ancestor()
72 	db = kernfs_depth(rb->kn, b);  in kernfs_common_ancestor()
126 	struct kernfs_node *kn, *common;  in kernfs_path_from_node_locked()  local
135 		kn_from = kernfs_root(kn_to)->kn;  in kernfs_path_from_node_locked()
158 		for (kn = kn_to, j = 0; j < i; j++)  in kernfs_path_from_node_locked()
159 			kn = kn->parent;  in kernfs_path_from_node_locked()
162 		len += strlcpy(buf + len, kn->name,  in kernfs_path_from_node_locked()
183 int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen)  in kernfs_name()  argument
189 	ret = kernfs_name_locked(kn, buf, buflen);  in kernfs_name()
229 void pr_cont_kernfs_name(struct kernfs_node *kn)  in pr_cont_kernfs_name()  argument
235 	kernfs_name_locked(kn, kernfs_pr_cont_buf, sizeof(kernfs_pr_cont_buf));  in pr_cont_kernfs_name()
247 void pr_cont_kernfs_path(struct kernfs_node *kn)  in pr_cont_kernfs_path()  argument
254 	sz = kernfs_path_from_node_locked(kn, NULL, kernfs_pr_cont_buf,  in pr_cont_kernfs_path()
279 struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn)  in kernfs_get_parent()  argument
285 	parent = kn->parent;  in kernfs_get_parent()
316 			       const void *ns, const struct kernfs_node *kn)  in kernfs_name_compare()  argument
318 	if (hash < kn->hash)  in kernfs_name_compare()
320 	if (hash > kn->hash)  in kernfs_name_compare()
322 	if (ns < kn->ns)  in kernfs_name_compare()
324 	if (ns > kn->ns)  in kernfs_name_compare()
326 	return strcmp(name, kn->name);  in kernfs_name_compare()
348 static int kernfs_link_sibling(struct kernfs_node *kn)  in kernfs_link_sibling()  argument
350 	struct rb_node **node = &kn->parent->dir.children.rb_node;  in kernfs_link_sibling()
359 		result = kernfs_sd_compare(kn, pos);  in kernfs_link_sibling()
369 	rb_link_node(&kn->rb, parent, node);  in kernfs_link_sibling()
370 	rb_insert_color(&kn->rb, &kn->parent->dir.children);  in kernfs_link_sibling()
373 	if (kernfs_type(kn) == KERNFS_DIR)  in kernfs_link_sibling()
374 		kn->parent->dir.subdirs++;  in kernfs_link_sibling()
390 static bool kernfs_unlink_sibling(struct kernfs_node *kn)  in kernfs_unlink_sibling()  argument
392 	if (RB_EMPTY_NODE(&kn->rb))  in kernfs_unlink_sibling()
395 	if (kernfs_type(kn) == KERNFS_DIR)  in kernfs_unlink_sibling()
396 		kn->parent->dir.subdirs--;  in kernfs_unlink_sibling()
398 	rb_erase(&kn->rb, &kn->parent->dir.children);  in kernfs_unlink_sibling()
399 	RB_CLEAR_NODE(&kn->rb);  in kernfs_unlink_sibling()
413 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn)  in kernfs_get_active()  argument
415 	if (unlikely(!kn))  in kernfs_get_active()
418 	if (!atomic_inc_unless_negative(&kn->active))  in kernfs_get_active()
421 	if (kernfs_lockdep(kn))  in kernfs_get_active()
422 		rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_);  in kernfs_get_active()
423 	return kn;  in kernfs_get_active()
433 void kernfs_put_active(struct kernfs_node *kn)  in kernfs_put_active()  argument
437 	if (unlikely(!kn))  in kernfs_put_active()
440 	if (kernfs_lockdep(kn))  in kernfs_put_active()
441 		rwsem_release(&kn->dep_map, _RET_IP_);  in kernfs_put_active()
442 	v = atomic_dec_return(&kn->active);  in kernfs_put_active()
446 	wake_up_all(&kernfs_root(kn)->deactivate_waitq);  in kernfs_put_active()
457 static void kernfs_drain(struct kernfs_node *kn)  in kernfs_drain()  argument
460 	struct kernfs_root *root = kernfs_root(kn);  in kernfs_drain()
463 	WARN_ON_ONCE(kernfs_active(kn));  in kernfs_drain()
467 	if (kernfs_lockdep(kn)) {  in kernfs_drain()
468 		rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);  in kernfs_drain()
469 		if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS)  in kernfs_drain()
470 			lock_contended(&kn->dep_map, _RET_IP_);  in kernfs_drain()
475 		   atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);  in kernfs_drain()
477 	if (kernfs_lockdep(kn)) {  in kernfs_drain()
478 		lock_acquired(&kn->dep_map, _RET_IP_);  in kernfs_drain()
479 		rwsem_release(&kn->dep_map, _RET_IP_);  in kernfs_drain()
482 	kernfs_drain_open_files(kn);  in kernfs_drain()
491 void kernfs_get(struct kernfs_node *kn)  in kernfs_get()  argument
493 	if (kn) {  in kernfs_get()
494 		WARN_ON(!atomic_read(&kn->count));  in kernfs_get()
495 		atomic_inc(&kn->count);  in kernfs_get()
506 void kernfs_put(struct kernfs_node *kn)  in kernfs_put()  argument
511 	if (!kn || !atomic_dec_and_test(&kn->count))  in kernfs_put()
513 	root = kernfs_root(kn);  in kernfs_put()
519 	parent = kn->parent;  in kernfs_put()
521 	WARN_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS,  in kernfs_put()
523 		  parent ? parent->name : "", kn->name, atomic_read(&kn->active));  in kernfs_put()
525 	if (kernfs_type(kn) == KERNFS_LINK)  in kernfs_put()
526 		kernfs_put(kn->symlink.target_kn);  in kernfs_put()
528 	kfree_const(kn->name);  in kernfs_put()
530 	if (kn->iattr) {  in kernfs_put()
531 		simple_xattrs_free(&kn->iattr->xattrs);  in kernfs_put()
532 		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);  in kernfs_put()
535 	idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));  in kernfs_put()
537 	kmem_cache_free(kernfs_node_cache, kn);  in kernfs_put()
539 	kn = parent;  in kernfs_put()
540 	if (kn) {  in kernfs_put()
541 		if (atomic_dec_and_test(&kn->count))  in kernfs_put()
553 	struct kernfs_node *kn;  in kernfs_dop_revalidate()  local
562 	kn = kernfs_dentry_node(dentry);  in kernfs_dop_revalidate()
566 	if (!kernfs_active(kn))  in kernfs_dop_revalidate()
570 	if (kernfs_dentry_node(dentry->d_parent) != kn->parent)  in kernfs_dop_revalidate()
574 	if (strcmp(dentry->d_name.name, kn->name) != 0)  in kernfs_dop_revalidate()
578 	if (kn->parent && kernfs_ns_enabled(kn->parent) &&  in kernfs_dop_revalidate()
579 	    kernfs_info(dentry->d_sb)->ns != kn->ns)  in kernfs_dop_revalidate()
619 	struct kernfs_node *kn;  in __kernfs_new_node()  local
627 	kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL);  in __kernfs_new_node()
628 	if (!kn)  in __kernfs_new_node()
633 	ret = idr_alloc_cyclic(&root->ino_idr, kn, 1, 0, GFP_ATOMIC);  in __kernfs_new_node()
643 	kn->id = (u64)id_highbits << 32 | ret;  in __kernfs_new_node()
645 	atomic_set(&kn->count, 1);  in __kernfs_new_node()
646 	atomic_set(&kn->active, KN_DEACTIVATED_BIAS);  in __kernfs_new_node()
647 	RB_CLEAR_NODE(&kn->rb);  in __kernfs_new_node()
649 	kn->name = name;  in __kernfs_new_node()
650 	kn->mode = mode;  in __kernfs_new_node()
651 	kn->flags = flags;  in __kernfs_new_node()
660 		ret = __kernfs_setattr(kn, &iattr);  in __kernfs_new_node()
666 		ret = security_kernfs_init_security(parent, kn);  in __kernfs_new_node()
671 	return kn;  in __kernfs_new_node()
674 	idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));  in __kernfs_new_node()
676 	kmem_cache_free(kernfs_node_cache, kn);  in __kernfs_new_node()
687 	struct kernfs_node *kn;  in kernfs_new_node()  local
689 	kn = __kernfs_new_node(kernfs_root(parent), parent,  in kernfs_new_node()
691 	if (kn) {  in kernfs_new_node()
693 		kn->parent = parent;  in kernfs_new_node()
695 	return kn;  in kernfs_new_node()
712 	struct kernfs_node *kn;  in kernfs_find_and_get_node_by_id()  local
718 	kn = idr_find(&root->ino_idr, (u32)ino);  in kernfs_find_and_get_node_by_id()
719 	if (!kn)  in kernfs_find_and_get_node_by_id()
724 		if (kernfs_ino(kn) != ino)  in kernfs_find_and_get_node_by_id()
728 		if (unlikely(gen && kernfs_gen(kn) != gen))  in kernfs_find_and_get_node_by_id()
737 	if (unlikely(!(kn->flags & KERNFS_ACTIVATED) ||  in kernfs_find_and_get_node_by_id()
738 		     !atomic_inc_not_zero(&kn->count)))  in kernfs_find_and_get_node_by_id()
742 	return kn;  in kernfs_find_and_get_node_by_id()
760 int kernfs_add_one(struct kernfs_node *kn)  in kernfs_add_one()  argument
762 	struct kernfs_node *parent = kn->parent;  in kernfs_add_one()
771 	if (WARN(has_ns != (bool)kn->ns, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",  in kernfs_add_one()
772 		 has_ns ? "required" : "invalid", parent->name, kn->name))  in kernfs_add_one()
785 	kn->hash = kernfs_name_hash(kn->name, kn->ns);  in kernfs_add_one()
787 	ret = kernfs_link_sibling(kn);  in kernfs_add_one()
807 	if (!(kernfs_root(kn)->flags & KERNFS_ROOT_CREATE_DEACTIVATED))  in kernfs_add_one()
808 		kernfs_activate(kn);  in kernfs_add_one()
843 		struct kernfs_node *kn;  in kernfs_find_ns()  local
846 		kn = rb_to_kn(node);  in kernfs_find_ns()
847 		result = kernfs_name_compare(hash, name, ns, kn);  in kernfs_find_ns()
853 			return kn;  in kernfs_find_ns()
903 	struct kernfs_node *kn;  in kernfs_find_and_get_ns()  local
906 	kn = kernfs_find_ns(parent, name, ns);  in kernfs_find_and_get_ns()
907 	kernfs_get(kn);  in kernfs_find_and_get_ns()
910 	return kn;  in kernfs_find_and_get_ns()
927 	struct kernfs_node *kn;  in kernfs_walk_and_get_ns()  local
930 	kn = kernfs_walk_ns(parent, path, ns);  in kernfs_walk_and_get_ns()
931 	kernfs_get(kn);  in kernfs_walk_and_get_ns()
934 	return kn;  in kernfs_walk_and_get_ns()
950 	struct kernfs_node *kn;  in kernfs_create_root()  local
970 	kn = __kernfs_new_node(root, NULL, "", S_IFDIR | S_IRUGO | S_IXUGO,  in kernfs_create_root()
973 	if (!kn) {  in kernfs_create_root()
979 	kn->priv = priv;  in kernfs_create_root()
980 	kn->dir.root = root;  in kernfs_create_root()
984 	root->kn = kn;  in kernfs_create_root()
988 		kernfs_activate(kn);  in kernfs_create_root()
1002 	kernfs_remove(root->kn);	/* will also free @root */  in kernfs_destroy_root()
1022 	struct kernfs_node *kn;  in kernfs_create_dir_ns()  local
1026 	kn = kernfs_new_node(parent, name, mode | S_IFDIR,  in kernfs_create_dir_ns()
1028 	if (!kn)  in kernfs_create_dir_ns()
1031 	kn->dir.root = parent->dir.root;  in kernfs_create_dir_ns()
1032 	kn->ns = ns;  in kernfs_create_dir_ns()
1033 	kn->priv = priv;  in kernfs_create_dir_ns()
1036 	rc = kernfs_add_one(kn);  in kernfs_create_dir_ns()
1038 		return kn;  in kernfs_create_dir_ns()
1040 	kernfs_put(kn);  in kernfs_create_dir_ns()
1054 	struct kernfs_node *kn;  in kernfs_create_empty_dir()  local
1058 	kn = kernfs_new_node(parent, name, S_IRUGO|S_IXUGO|S_IFDIR,  in kernfs_create_empty_dir()
1060 	if (!kn)  in kernfs_create_empty_dir()
1063 	kn->flags |= KERNFS_EMPTY_DIR;  in kernfs_create_empty_dir()
1064 	kn->dir.root = parent->dir.root;  in kernfs_create_empty_dir()
1065 	kn->ns = NULL;  in kernfs_create_empty_dir()
1066 	kn->priv = NULL;  in kernfs_create_empty_dir()
1069 	rc = kernfs_add_one(kn);  in kernfs_create_empty_dir()
1071 		return kn;  in kernfs_create_empty_dir()
1073 	kernfs_put(kn);  in kernfs_create_empty_dir()
1083 	struct kernfs_node *kn;  in kernfs_iop_lookup()  local
1092 	kn = kernfs_find_ns(parent, dentry->d_name.name, ns);  in kernfs_iop_lookup()
1095 	if (!kn || !kernfs_active(kn)) {  in kernfs_iop_lookup()
1101 	inode = kernfs_get_inode(dir->i_sb, kn);  in kernfs_iop_lookup()
1135 	struct kernfs_node *kn  = kernfs_dentry_node(dentry);  in kernfs_iop_rmdir()  local
1136 	struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops;  in kernfs_iop_rmdir()
1142 	if (!kernfs_get_active(kn))  in kernfs_iop_rmdir()
1145 	ret = scops->rmdir(kn);  in kernfs_iop_rmdir()
1147 	kernfs_put_active(kn);  in kernfs_iop_rmdir()
1155 	struct kernfs_node *kn = kernfs_dentry_node(old_dentry);  in kernfs_iop_rename()  local
1157 	struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops;  in kernfs_iop_rename()
1166 	if (!kernfs_get_active(kn))  in kernfs_iop_rename()
1170 		kernfs_put_active(kn);  in kernfs_iop_rename()
1174 	ret = scops->rename(kn, new_parent, new_dentry->d_name.name);  in kernfs_iop_rename()
1177 	kernfs_put_active(kn);  in kernfs_iop_rename()
1261 void kernfs_activate(struct kernfs_node *kn)  in kernfs_activate()  argument
1268 	while ((pos = kernfs_next_descendant_post(pos, kn))) {  in kernfs_activate()
1282 static void __kernfs_remove(struct kernfs_node *kn)  in __kernfs_remove()  argument
1293 	if (!kn || (kn->parent && RB_EMPTY_NODE(&kn->rb)))  in __kernfs_remove()
1296 	pr_debug("kernfs %s: removing\n", kn->name);  in __kernfs_remove()
1300 	while ((pos = kernfs_next_descendant_post(pos, kn)))  in __kernfs_remove()
1306 		pos = kernfs_leftmost_descendant(kn);  in __kernfs_remove()
1322 		if (kn->flags & KERNFS_ACTIVATED)  in __kernfs_remove()
1325 			WARN_ON_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS);  in __kernfs_remove()
1345 	} while (pos != kn);  in __kernfs_remove()
1354 void kernfs_remove(struct kernfs_node *kn)  in kernfs_remove()  argument
1357 	__kernfs_remove(kn);  in kernfs_remove()
1375 void kernfs_break_active_protection(struct kernfs_node *kn)  in kernfs_break_active_protection()  argument
1381 	kernfs_put_active(kn);  in kernfs_break_active_protection()
1399 void kernfs_unbreak_active_protection(struct kernfs_node *kn)  in kernfs_unbreak_active_protection()  argument
1410 	atomic_inc(&kn->active);  in kernfs_unbreak_active_protection()
1411 	if (kernfs_lockdep(kn))  in kernfs_unbreak_active_protection()
1412 		rwsem_acquire(&kn->dep_map, 0, 1, _RET_IP_);  in kernfs_unbreak_active_protection()
1441 bool kernfs_remove_self(struct kernfs_node *kn)  in kernfs_remove_self()  argument
1446 	kernfs_break_active_protection(kn);  in kernfs_remove_self()
1457 	if (!(kn->flags & KERNFS_SUICIDAL)) {  in kernfs_remove_self()
1458 		kn->flags |= KERNFS_SUICIDAL;  in kernfs_remove_self()
1459 		__kernfs_remove(kn);  in kernfs_remove_self()
1460 		kn->flags |= KERNFS_SUICIDED;  in kernfs_remove_self()
1463 		wait_queue_head_t *waitq = &kernfs_root(kn)->deactivate_waitq;  in kernfs_remove_self()
1469 			if ((kn->flags & KERNFS_SUICIDED) &&  in kernfs_remove_self()
1470 			    atomic_read(&kn->active) == KN_DEACTIVATED_BIAS)  in kernfs_remove_self()
1478 		WARN_ON_ONCE(!RB_EMPTY_NODE(&kn->rb));  in kernfs_remove_self()
1486 	kernfs_unbreak_active_protection(kn);  in kernfs_remove_self()
1504 	struct kernfs_node *kn;  in kernfs_remove_by_name_ns()  local
1514 	kn = kernfs_find_ns(parent, name, ns);  in kernfs_remove_by_name_ns()
1515 	if (kn)  in kernfs_remove_by_name_ns()
1516 		__kernfs_remove(kn);  in kernfs_remove_by_name_ns()
1520 	if (kn)  in kernfs_remove_by_name_ns()
1533 int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,  in kernfs_rename_ns()  argument
1541 	if (!kn->parent)  in kernfs_rename_ns()
1547 	if (!kernfs_active(kn) || !kernfs_active(new_parent) ||  in kernfs_rename_ns()
1552 	if ((kn->parent == new_parent) && (kn->ns == new_ns) &&  in kernfs_rename_ns()
1553 	    (strcmp(kn->name, new_name) == 0))  in kernfs_rename_ns()
1561 	if (strcmp(kn->name, new_name) != 0) {  in kernfs_rename_ns()
1573 	kernfs_unlink_sibling(kn);  in kernfs_rename_ns()
1579 	old_parent = kn->parent;  in kernfs_rename_ns()
1580 	kn->parent = new_parent;  in kernfs_rename_ns()
1582 	kn->ns = new_ns;  in kernfs_rename_ns()
1584 		old_name = kn->name;  in kernfs_rename_ns()
1585 		kn->name = new_name;  in kernfs_rename_ns()
1590 	kn->hash = kernfs_name_hash(kn->name, kn->ns);  in kernfs_rename_ns()
1591 	kernfs_link_sibling(kn);  in kernfs_rename_ns()
1603 static inline unsigned char dt_type(struct kernfs_node *kn)  in dt_type()  argument
1605 	return (kn->mode >> 12) & 15;  in dt_type()