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, 1, _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, 1, _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
515 	if (!kn || !atomic_dec_and_test(&kn->count))  in kernfs_put()
517 	root = kernfs_root(kn);  in kernfs_put()
523 	parent = kn->parent;  in kernfs_put()
525 	WARN_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS,  in kernfs_put()
527 		  parent ? parent->name : "", kn->name, atomic_read(&kn->active));  in kernfs_put()
529 	if (kernfs_type(kn) == KERNFS_LINK)  in kernfs_put()
530 		kernfs_put(kn->symlink.target_kn);  in kernfs_put()
532 	kfree_const(kn->name);  in kernfs_put()
534 	if (kn->iattr) {  in kernfs_put()
535 		simple_xattrs_free(&kn->iattr->xattrs);  in kernfs_put()
536 		kmem_cache_free(kernfs_iattrs_cache, kn->iattr);  in kernfs_put()
539 	idr_remove(&root->ino_idr, kn->id.ino);  in kernfs_put()
541 	kmem_cache_free(kernfs_node_cache, kn);  in kernfs_put()
543 	kn = parent;  in kernfs_put()
544 	if (kn) {  in kernfs_put()
545 		if (atomic_dec_and_test(&kn->count))  in kernfs_put()
557 	struct kernfs_node *kn;  in kernfs_dop_revalidate()  local
566 	kn = kernfs_dentry_node(dentry);  in kernfs_dop_revalidate()
570 	if (!kernfs_active(kn))  in kernfs_dop_revalidate()
574 	if (kernfs_dentry_node(dentry->d_parent) != kn->parent)  in kernfs_dop_revalidate()
578 	if (strcmp(dentry->d_name.name, kn->name) != 0)  in kernfs_dop_revalidate()
582 	if (kn->parent && kernfs_ns_enabled(kn->parent) &&  in kernfs_dop_revalidate()
583 	    kernfs_info(dentry->d_sb)->ns != kn->ns)  in kernfs_dop_revalidate()
623 	struct kernfs_node *kn;  in __kernfs_new_node()  local
632 	kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL);  in __kernfs_new_node()
633 	if (!kn)  in __kernfs_new_node()
639 	ret = idr_alloc_cyclic(&root->ino_idr, kn, 1, 0, GFP_ATOMIC);  in __kernfs_new_node()
647 	kn->id.ino = ret;  in __kernfs_new_node()
648 	kn->id.generation = gen;  in __kernfs_new_node()
654 	atomic_set_release(&kn->count, 1);  in __kernfs_new_node()
655 	atomic_set(&kn->active, KN_DEACTIVATED_BIAS);  in __kernfs_new_node()
656 	RB_CLEAR_NODE(&kn->rb);  in __kernfs_new_node()
658 	kn->name = name;  in __kernfs_new_node()
659 	kn->mode = mode;  in __kernfs_new_node()
660 	kn->flags = flags;  in __kernfs_new_node()
669 		ret = __kernfs_setattr(kn, &iattr);  in __kernfs_new_node()
675 		ret = security_kernfs_init_security(parent, kn);  in __kernfs_new_node()
680 	return kn;  in __kernfs_new_node()
683 	idr_remove(&root->ino_idr, kn->id.ino);  in __kernfs_new_node()
685 	kmem_cache_free(kernfs_node_cache, kn);  in __kernfs_new_node()
696 	struct kernfs_node *kn;  in kernfs_new_node()  local
698 	kn = __kernfs_new_node(kernfs_root(parent), parent,  in kernfs_new_node()
700 	if (kn) {  in kernfs_new_node()
702 		kn->parent = parent;  in kernfs_new_node()
704 	return kn;  in kernfs_new_node()
718 	struct kernfs_node *kn;  in kernfs_find_and_get_node_by_ino()  local
721 	kn = idr_find(&root->ino_idr, ino);  in kernfs_find_and_get_node_by_ino()
722 	if (!kn)  in kernfs_find_and_get_node_by_ino()
732 	if (!atomic_inc_not_zero(&kn->count)) {  in kernfs_find_and_get_node_by_ino()
733 		kn = NULL;  in kernfs_find_and_get_node_by_ino()
744 	if (kn->id.ino != ino)  in kernfs_find_and_get_node_by_ino()
748 	return kn;  in kernfs_find_and_get_node_by_ino()
751 	kernfs_put(kn);  in kernfs_find_and_get_node_by_ino()
767 int kernfs_add_one(struct kernfs_node *kn)  in kernfs_add_one()  argument
769 	struct kernfs_node *parent = kn->parent;  in kernfs_add_one()
778 	if (WARN(has_ns != (bool)kn->ns, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",  in kernfs_add_one()
779 		 has_ns ? "required" : "invalid", parent->name, kn->name))  in kernfs_add_one()
792 	kn->hash = kernfs_name_hash(kn->name, kn->ns);  in kernfs_add_one()
794 	ret = kernfs_link_sibling(kn);  in kernfs_add_one()
814 	if (!(kernfs_root(kn)->flags & KERNFS_ROOT_CREATE_DEACTIVATED))  in kernfs_add_one()
815 		kernfs_activate(kn);  in kernfs_add_one()
850 		struct kernfs_node *kn;  in kernfs_find_ns()  local
853 		kn = rb_to_kn(node);  in kernfs_find_ns()
854 		result = kernfs_name_compare(hash, name, ns, kn);  in kernfs_find_ns()
860 			return kn;  in kernfs_find_ns()
910 	struct kernfs_node *kn;  in kernfs_find_and_get_ns()  local
913 	kn = kernfs_find_ns(parent, name, ns);  in kernfs_find_and_get_ns()
914 	kernfs_get(kn);  in kernfs_find_and_get_ns()
917 	return kn;  in kernfs_find_and_get_ns()
934 	struct kernfs_node *kn;  in kernfs_walk_and_get_ns()  local
937 	kn = kernfs_walk_ns(parent, path, ns);  in kernfs_walk_and_get_ns()
938 	kernfs_get(kn);  in kernfs_walk_and_get_ns()
941 	return kn;  in kernfs_walk_and_get_ns()
957 	struct kernfs_node *kn;  in kernfs_create_root()  local
967 	kn = __kernfs_new_node(root, NULL, "", S_IFDIR | S_IRUGO | S_IXUGO,  in kernfs_create_root()
970 	if (!kn) {  in kernfs_create_root()
976 	kn->priv = priv;  in kernfs_create_root()
977 	kn->dir.root = root;  in kernfs_create_root()
981 	root->kn = kn;  in kernfs_create_root()
985 		kernfs_activate(kn);  in kernfs_create_root()
999 	kernfs_remove(root->kn);	/* will also free @root */  in kernfs_destroy_root()
1019 	struct kernfs_node *kn;  in kernfs_create_dir_ns()  local
1023 	kn = kernfs_new_node(parent, name, mode | S_IFDIR,  in kernfs_create_dir_ns()
1025 	if (!kn)  in kernfs_create_dir_ns()
1028 	kn->dir.root = parent->dir.root;  in kernfs_create_dir_ns()
1029 	kn->ns = ns;  in kernfs_create_dir_ns()
1030 	kn->priv = priv;  in kernfs_create_dir_ns()
1033 	rc = kernfs_add_one(kn);  in kernfs_create_dir_ns()
1035 		return kn;  in kernfs_create_dir_ns()
1037 	kernfs_put(kn);  in kernfs_create_dir_ns()
1051 	struct kernfs_node *kn;  in kernfs_create_empty_dir()  local
1055 	kn = kernfs_new_node(parent, name, S_IRUGO|S_IXUGO|S_IFDIR,  in kernfs_create_empty_dir()
1057 	if (!kn)  in kernfs_create_empty_dir()
1060 	kn->flags |= KERNFS_EMPTY_DIR;  in kernfs_create_empty_dir()
1061 	kn->dir.root = parent->dir.root;  in kernfs_create_empty_dir()
1062 	kn->ns = NULL;  in kernfs_create_empty_dir()
1063 	kn->priv = NULL;  in kernfs_create_empty_dir()
1066 	rc = kernfs_add_one(kn);  in kernfs_create_empty_dir()
1068 		return kn;  in kernfs_create_empty_dir()
1070 	kernfs_put(kn);  in kernfs_create_empty_dir()
1080 	struct kernfs_node *kn;  in kernfs_iop_lookup()  local
1089 	kn = kernfs_find_ns(parent, dentry->d_name.name, ns);  in kernfs_iop_lookup()
1092 	if (!kn || !kernfs_active(kn)) {  in kernfs_iop_lookup()
1098 	inode = kernfs_get_inode(dir->i_sb, kn);  in kernfs_iop_lookup()
1132 	struct kernfs_node *kn  = kernfs_dentry_node(dentry);  in kernfs_iop_rmdir()  local
1133 	struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops;  in kernfs_iop_rmdir()
1139 	if (!kernfs_get_active(kn))  in kernfs_iop_rmdir()
1142 	ret = scops->rmdir(kn);  in kernfs_iop_rmdir()
1144 	kernfs_put_active(kn);  in kernfs_iop_rmdir()
1152 	struct kernfs_node *kn = kernfs_dentry_node(old_dentry);  in kernfs_iop_rename()  local
1154 	struct kernfs_syscall_ops *scops = kernfs_root(kn)->syscall_ops;  in kernfs_iop_rename()
1163 	if (!kernfs_get_active(kn))  in kernfs_iop_rename()
1167 		kernfs_put_active(kn);  in kernfs_iop_rename()
1171 	ret = scops->rename(kn, new_parent, new_dentry->d_name.name);  in kernfs_iop_rename()
1174 	kernfs_put_active(kn);  in kernfs_iop_rename()
1258 void kernfs_activate(struct kernfs_node *kn)  in kernfs_activate()  argument
1265 	while ((pos = kernfs_next_descendant_post(pos, kn))) {  in kernfs_activate()
1279 static void __kernfs_remove(struct kernfs_node *kn)  in __kernfs_remove()  argument
1290 	if (!kn || (kn->parent && RB_EMPTY_NODE(&kn->rb)))  in __kernfs_remove()
1293 	pr_debug("kernfs %s: removing\n", kn->name);  in __kernfs_remove()
1297 	while ((pos = kernfs_next_descendant_post(pos, kn)))  in __kernfs_remove()
1303 		pos = kernfs_leftmost_descendant(kn);  in __kernfs_remove()
1319 		if (kn->flags & KERNFS_ACTIVATED)  in __kernfs_remove()
1322 			WARN_ON_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS);  in __kernfs_remove()
1342 	} while (pos != kn);  in __kernfs_remove()
1351 void kernfs_remove(struct kernfs_node *kn)  in kernfs_remove()  argument
1354 	__kernfs_remove(kn);  in kernfs_remove()
1372 void kernfs_break_active_protection(struct kernfs_node *kn)  in kernfs_break_active_protection()  argument
1378 	kernfs_put_active(kn);  in kernfs_break_active_protection()
1396 void kernfs_unbreak_active_protection(struct kernfs_node *kn)  in kernfs_unbreak_active_protection()  argument
1407 	atomic_inc(&kn->active);  in kernfs_unbreak_active_protection()
1408 	if (kernfs_lockdep(kn))  in kernfs_unbreak_active_protection()
1409 		rwsem_acquire(&kn->dep_map, 0, 1, _RET_IP_);  in kernfs_unbreak_active_protection()
1438 bool kernfs_remove_self(struct kernfs_node *kn)  in kernfs_remove_self()  argument
1443 	kernfs_break_active_protection(kn);  in kernfs_remove_self()
1454 	if (!(kn->flags & KERNFS_SUICIDAL)) {  in kernfs_remove_self()
1455 		kn->flags |= KERNFS_SUICIDAL;  in kernfs_remove_self()
1456 		__kernfs_remove(kn);  in kernfs_remove_self()
1457 		kn->flags |= KERNFS_SUICIDED;  in kernfs_remove_self()
1460 		wait_queue_head_t *waitq = &kernfs_root(kn)->deactivate_waitq;  in kernfs_remove_self()
1466 			if ((kn->flags & KERNFS_SUICIDED) &&  in kernfs_remove_self()
1467 			    atomic_read(&kn->active) == KN_DEACTIVATED_BIAS)  in kernfs_remove_self()
1475 		WARN_ON_ONCE(!RB_EMPTY_NODE(&kn->rb));  in kernfs_remove_self()
1483 	kernfs_unbreak_active_protection(kn);  in kernfs_remove_self()
1501 	struct kernfs_node *kn;  in kernfs_remove_by_name_ns()  local
1511 	kn = kernfs_find_ns(parent, name, ns);  in kernfs_remove_by_name_ns()
1512 	if (kn)  in kernfs_remove_by_name_ns()
1513 		__kernfs_remove(kn);  in kernfs_remove_by_name_ns()
1517 	if (kn)  in kernfs_remove_by_name_ns()
1530 int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,  in kernfs_rename_ns()  argument
1538 	if (!kn->parent)  in kernfs_rename_ns()
1544 	if (!kernfs_active(kn) || !kernfs_active(new_parent) ||  in kernfs_rename_ns()
1549 	if ((kn->parent == new_parent) && (kn->ns == new_ns) &&  in kernfs_rename_ns()
1550 	    (strcmp(kn->name, new_name) == 0))  in kernfs_rename_ns()
1558 	if (strcmp(kn->name, new_name) != 0) {  in kernfs_rename_ns()
1570 	kernfs_unlink_sibling(kn);  in kernfs_rename_ns()
1576 	old_parent = kn->parent;  in kernfs_rename_ns()
1577 	kn->parent = new_parent;  in kernfs_rename_ns()
1579 	kn->ns = new_ns;  in kernfs_rename_ns()
1581 		old_name = kn->name;  in kernfs_rename_ns()
1582 		kn->name = new_name;  in kernfs_rename_ns()
1587 	kn->hash = kernfs_name_hash(kn->name, kn->ns);  in kernfs_rename_ns()
1588 	kernfs_link_sibling(kn);  in kernfs_rename_ns()
1600 static inline unsigned char dt_type(struct kernfs_node *kn)  in dt_type()  argument
1602 	return (kn->mode >> 12) & 15;  in dt_type()