1 // SPDX-License-Identifier: GPL-2.0-only
19 	return list_entry(p->mnt_share.next, struct mount, mnt_share);  in next_peer()
24 	return list_entry(p->mnt_slave_list.next, struct mount, mnt_slave);  in first_slave()
29 	return list_entry(p->mnt_slave_list.prev, struct mount, mnt_slave);  in last_slave()
34 	return list_entry(p->mnt_slave.next, struct mount, mnt_slave);  in next_slave()
45 		if (m->mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root))  in get_peer_under_root()
64 	for (m = mnt->mnt_master; m != NULL; m = m->mnt_master) {  in get_dominating_id()
65 		struct mount *d = get_peer_under_root(m, mnt->mnt_ns, root);  in get_dominating_id()
67 			return d->mnt_group_id;  in get_dominating_id()
77 	if (list_empty(&mnt->mnt_share)) {  in do_make_slave()
82 		master = mnt->mnt_master;  in do_make_slave()
84 			struct list_head *p = &mnt->mnt_slave_list;  in do_make_slave()
88 				list_del_init(&slave_mnt->mnt_slave);  in do_make_slave()
89 				slave_mnt->mnt_master = NULL;  in do_make_slave()
101 			if (m->mnt.mnt_root == mnt->mnt.mnt_root) {  in do_make_slave()
106 		list_del_init(&mnt->mnt_share);  in do_make_slave()
107 		mnt->mnt_group_id = 0;  in do_make_slave()
110 	list_for_each_entry(slave_mnt, &mnt->mnt_slave_list, mnt_slave)  in do_make_slave()
111 		slave_mnt->mnt_master = master;  in do_make_slave()
112 	list_move(&mnt->mnt_slave, &master->mnt_slave_list);  in do_make_slave()
113 	list_splice(&mnt->mnt_slave_list, master->mnt_slave_list.prev);  in do_make_slave()
114 	INIT_LIST_HEAD(&mnt->mnt_slave_list);  in do_make_slave()
115 	mnt->mnt_master = master;  in do_make_slave()
130 		list_del_init(&mnt->mnt_slave);  in change_mnt_propagation()
131 		mnt->mnt_master = NULL;  in change_mnt_propagation()
133 			mnt->mnt.mnt_flags |= MNT_UNBINDABLE;  in change_mnt_propagation()
135 			mnt->mnt.mnt_flags &= ~MNT_UNBINDABLE;  in change_mnt_propagation()
153 	if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list))  in propagation_next()
157 		struct mount *master = m->mnt_master;  in propagation_next()
159 		if (master == origin->mnt_master) {  in propagation_next()
162 		} else if (m->mnt_slave.next != &master->mnt_slave_list)  in propagation_next()
177 	if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list))  in skip_propagation_subtree()
188 			if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list))  in next_group()
191 			if (m->mnt_group_id == origin->mnt_group_id) {  in next_group()
194 			} else if (m->mnt_slave.next != &next->mnt_slave)  in next_group()
200 			struct mount *master = m->mnt_master;  in next_group()
201 			if (m->mnt_slave.next != &master->mnt_slave_list)  in next_group()
204 			if (master->mnt_group_id == origin->mnt_group_id)  in next_group()
206 			if (master->mnt_slave.next == &m->mnt_slave)  in next_group()
221 	return m1->mnt_group_id == m2->mnt_group_id && m1->mnt_group_id;  in peers()
226 	struct mount *child;  in propagate_one()  local
232 	if (!is_subdir(dest_mp->m_dentry, m->mnt.mnt_root))  in propagate_one()
240 			p = n->mnt_master;  in propagate_one()
245 			struct mount *parent = last_source->mnt_parent;  in propagate_one()  local
248 			done = parent->mnt_master == p;  in propagate_one()
249 			if (done && peers(n, parent))  in propagate_one()
251 			last_source = last_source->mnt_master;  in propagate_one()
260 	child = copy_tree(last_source, last_source->mnt.mnt_root, type);  in propagate_one()
261 	if (IS_ERR(child))  in propagate_one()
262 		return PTR_ERR(child);  in propagate_one()
264 	mnt_set_mountpoint(m, dest_mp, child);  in propagate_one()
265 	if (m->mnt_master != dest_master)  in propagate_one()
266 		SET_MNT_MARK(m->mnt_master);  in propagate_one()
269 	last_source = child;  in propagate_one()
270 	hlist_add_head(&child->mnt_hash, list);  in propagate_one()
271 	return count_mounts(m->mnt_ns, child);  in propagate_one()
279  * source_mnt. Also link all the new mounts using ->mnt_list
280  * headed at source_mnt's ->mnt_list
302 	dest_master = dest_mnt->mnt_master;  in propagate_mnt()
326 		m = n->mnt_parent;  in propagate_mnt()
327 		if (m->mnt_master != dest_mnt->mnt_master)  in propagate_mnt()
328 			CLEAR_MNT_MARK(m->mnt_master);  in propagate_mnt()
337 	struct mount *child;  in find_topper()  local
339 	if (!list_is_singular(&mnt->mnt_mounts))  in find_topper()
342 	child = list_first_entry(&mnt->mnt_mounts, struct mount, mnt_child);  in find_topper()
343 	if (child->mnt_mountpoint != mnt->mnt.mnt_root)  in find_topper()
346 	return child;  in find_topper()
358  * propagation_would_overmount - check whether propagation from @from
386 	if (to->mnt.mnt_root != mp->m_dentry)  in propagation_would_overmount()
389 	for (const struct mount *m = to; m; m = m->mnt_master) {  in propagation_would_overmount()
401  * other mounts its parent propagates to.
409 	struct mount *m, *child, *topper;  in propagate_mount_busy()  local
410 	struct mount *parent = mnt->mnt_parent;  in propagate_mount_busy()  local
412 	if (mnt == parent)  in propagate_mount_busy()
420 	if (!list_empty(&mnt->mnt_mounts) || do_refcount_check(mnt, refcnt))  in propagate_mount_busy()
423 	for (m = propagation_next(parent, parent); m;  in propagate_mount_busy()
424 	     		m = propagation_next(m, parent)) {  in propagate_mount_busy()
426 		child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint);  in propagate_mount_busy()
427 		if (!child)  in propagate_mount_busy()
430 		/* Is there exactly one mount on the child that covers  in propagate_mount_busy()
433 		topper = find_topper(child);  in propagate_mount_busy()
436 		else if (!list_empty(&child->mnt_mounts))  in propagate_mount_busy()
439 		if (do_refcount_check(child, count))  in propagate_mount_busy()
452 	struct mount *parent = mnt->mnt_parent;  in propagate_mount_unlock()  local
453 	struct mount *m, *child;  in propagate_mount_unlock()  local
455 	BUG_ON(parent == mnt);  in propagate_mount_unlock()
457 	for (m = propagation_next(parent, parent); m;  in propagate_mount_unlock()
458 			m = propagation_next(m, parent)) {  in propagate_mount_unlock()
459 		child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint);  in propagate_mount_unlock()
460 		if (child)  in propagate_mount_unlock()
461 			child->mnt.mnt_flags &= ~MNT_LOCKED;  in propagate_mount_unlock()
468 	mnt->mnt.mnt_flags |= MNT_UMOUNT;  in umount_one()
469 	list_del_init(&mnt->mnt_child);  in umount_one()
470 	list_del_init(&mnt->mnt_umounting);  in umount_one()
471 	list_move_tail(&mnt->mnt_list, to_umount);  in umount_one()
476  * parent propagates to.
483 	struct mount *child;  in __propagate_umount()  local
486 	 * The state of the parent won't change if this mount is  in __propagate_umount()
489 	if (mnt->mnt.mnt_flags & (MNT_UMOUNT | MNT_MARKED))  in __propagate_umount()
495 	list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) {  in __propagate_umount()
496 		if (child->mnt_mountpoint == mnt->mnt.mnt_root)  in __propagate_umount()
498 		if (!list_empty(&child->mnt_umounting) && IS_MNT_MARKED(child))  in __propagate_umount()
500 		/* Found a mounted child */  in __propagate_umount()
513 		list_move_tail(&mnt->mnt_umounting, to_restore);  in __propagate_umount()
522 	struct mount *mnt, *child, *tmp;  in umount_list()  local
524 		list_for_each_entry_safe(child, tmp, &mnt->mnt_mounts, mnt_child) {  in umount_list()
526 			if (child->mnt_mountpoint == mnt->mnt.mnt_root)  in umount_list()
527 				list_move_tail(&child->mnt_umounting, to_restore);  in umount_list()
529 				umount_one(child, to_umount);  in umount_list()
538 		struct mount *mnt, *parent;  in restore_mounts()  local
543 		list_del_init(&mnt->mnt_umounting);  in restore_mounts()
546 		mp = mnt->mnt_mp;  in restore_mounts()
547 		parent = mnt->mnt_parent;  in restore_mounts()
548 		while (parent->mnt.mnt_flags & MNT_UMOUNT) {  in restore_mounts()
549 			mp = parent->mnt_mp;  in restore_mounts()
550 			parent = parent->mnt_parent;  in restore_mounts()
552 		if (parent != mnt->mnt_parent)  in restore_mounts()
553 			mnt_change_mountpoint(parent, mp, mnt);  in restore_mounts()
562 		list_del_init(&mnt->mnt_umounting);  in cleanup_umount_visitations()
582 		struct mount *parent = mnt->mnt_parent;  in propagate_umount()  local
591 		if (!list_empty(&mnt->mnt_umounting))  in propagate_umount()
594 		list_add_tail(&mnt->mnt_umounting, &visited);  in propagate_umount()
595 		for (m = propagation_next(parent, parent); m;  in propagate_umount()
596 		     m = propagation_next(m, parent)) {  in propagate_umount()
597 			struct mount *child = __lookup_mnt(&m->mnt,  in propagate_umount()  local
598 							   mnt->mnt_mountpoint);  in propagate_umount()
599 			if (!child)  in propagate_umount()
602 			if (!list_empty(&child->mnt_umounting)) {  in propagate_umount()
604 				 * If the child has already been visited it is  in propagate_umount()
610 				m = skip_propagation_subtree(m, parent);  in propagate_umount()
612 			} else if (child->mnt.mnt_flags & MNT_UMOUNT) {  in propagate_umount()
619 				list_add_tail(&child->mnt_umounting, &visited);  in propagate_umount()
623 			/* Check the child and parents while progress is made */  in propagate_umount()
624 			while (__propagate_umount(child,  in propagate_umount()
626 				/* Is the parent a umount candidate? */  in propagate_umount()
627 				child = child->mnt_parent;  in propagate_umount()
628 				if (list_empty(&child->mnt_umounting))  in propagate_umount()