84 static inline struct hlist_head *m_hash(struct vfsmount *mnt, struct dentry *dentry)  in m_hash()  argument
86 	unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES);  in m_hash()
99 static int mnt_alloc_id(struct mount *mnt)  in mnt_alloc_id()  argument
105 	mnt->mnt_id = res;  in mnt_alloc_id()
109 static void mnt_free_id(struct mount *mnt)  in mnt_free_id()  argument
111 	ida_free(&mnt_id_ida, mnt->mnt_id);  in mnt_free_id()
117 static int mnt_alloc_group_id(struct mount *mnt)  in mnt_alloc_group_id()  argument
123 	mnt->mnt_group_id = res;  in mnt_alloc_group_id()
130 void mnt_release_group_id(struct mount *mnt)  in mnt_release_group_id()  argument
132 	ida_free(&mnt_group_ida, mnt->mnt_group_id);  in mnt_release_group_id()
133 	mnt->mnt_group_id = 0;  in mnt_release_group_id()
139 static inline void mnt_add_count(struct mount *mnt, int n)  in mnt_add_count()  argument
142 	this_cpu_add(mnt->mnt_pcp->mnt_count, n);  in mnt_add_count()
145 	mnt->mnt_count += n;  in mnt_add_count()
153 unsigned int mnt_get_count(struct mount *mnt)  in mnt_get_count()  argument
160 		count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_count;  in mnt_get_count()
165 	return mnt->mnt_count;  in mnt_get_count()
174 	mntput(&m->mnt);  in drop_mountpoint()
179 	struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);  in alloc_vfsmnt()  local
180 	if (mnt) {  in alloc_vfsmnt()
183 		err = mnt_alloc_id(mnt);  in alloc_vfsmnt()
188 			mnt->mnt_devname = kstrdup_const(name, GFP_KERNEL);  in alloc_vfsmnt()
189 			if (!mnt->mnt_devname)  in alloc_vfsmnt()
194 		mnt->mnt_pcp = alloc_percpu(struct mnt_pcp);  in alloc_vfsmnt()
195 		if (!mnt->mnt_pcp)  in alloc_vfsmnt()
198 		this_cpu_add(mnt->mnt_pcp->mnt_count, 1);  in alloc_vfsmnt()
200 		mnt->mnt_count = 1;  in alloc_vfsmnt()
201 		mnt->mnt_writers = 0;  in alloc_vfsmnt()
204 		INIT_HLIST_NODE(&mnt->mnt_hash);  in alloc_vfsmnt()
205 		INIT_LIST_HEAD(&mnt->mnt_child);  in alloc_vfsmnt()
206 		INIT_LIST_HEAD(&mnt->mnt_mounts);  in alloc_vfsmnt()
207 		INIT_LIST_HEAD(&mnt->mnt_list);  in alloc_vfsmnt()
208 		INIT_LIST_HEAD(&mnt->mnt_expire);  in alloc_vfsmnt()
209 		INIT_LIST_HEAD(&mnt->mnt_share);  in alloc_vfsmnt()
210 		INIT_LIST_HEAD(&mnt->mnt_slave_list);  in alloc_vfsmnt()
211 		INIT_LIST_HEAD(&mnt->mnt_slave);  in alloc_vfsmnt()
212 		INIT_HLIST_NODE(&mnt->mnt_mp_list);  in alloc_vfsmnt()
213 		INIT_LIST_HEAD(&mnt->mnt_umounting);  in alloc_vfsmnt()
214 		init_fs_pin(&mnt->mnt_umount, drop_mountpoint);  in alloc_vfsmnt()
216 	return mnt;  in alloc_vfsmnt()
220 	kfree_const(mnt->mnt_devname);  in alloc_vfsmnt()
223 	mnt_free_id(mnt);  in alloc_vfsmnt()
225 	kmem_cache_free(mnt_cache, mnt);  in alloc_vfsmnt()
248 int __mnt_is_readonly(struct vfsmount *mnt)  in __mnt_is_readonly()  argument
250 	if (mnt->mnt_flags & MNT_READONLY)  in __mnt_is_readonly()
252 	if (sb_rdonly(mnt->mnt_sb))  in __mnt_is_readonly()
258 static inline void mnt_inc_writers(struct mount *mnt)  in mnt_inc_writers()  argument
261 	this_cpu_inc(mnt->mnt_pcp->mnt_writers);  in mnt_inc_writers()
263 	mnt->mnt_writers++;  in mnt_inc_writers()
267 static inline void mnt_dec_writers(struct mount *mnt)  in mnt_dec_writers()  argument
270 	this_cpu_dec(mnt->mnt_pcp->mnt_writers);  in mnt_dec_writers()
272 	mnt->mnt_writers--;  in mnt_dec_writers()
276 static unsigned int mnt_get_writers(struct mount *mnt)  in mnt_get_writers()  argument
283 		count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_writers;  in mnt_get_writers()
288 	return mnt->mnt_writers;  in mnt_get_writers()
292 static int mnt_is_readonly(struct vfsmount *mnt)  in mnt_is_readonly()  argument
294 	if (mnt->mnt_sb->s_readonly_remount)  in mnt_is_readonly()
298 	return __mnt_is_readonly(mnt);  in mnt_is_readonly()
319 	struct mount *mnt = real_mount(m);  in __mnt_want_write()  local
323 	mnt_inc_writers(mnt);  in __mnt_want_write()
330 	while (READ_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)  in __mnt_want_write()
339 		mnt_dec_writers(mnt);  in __mnt_want_write()
380 int mnt_clone_write(struct vfsmount *mnt)  in mnt_clone_write()  argument
383 	if (__mnt_is_readonly(mnt))  in mnt_clone_write()
386 	mnt_inc_writers(real_mount(mnt));  in mnt_clone_write()
402 		return __mnt_want_write(file->f_path.mnt);  in __mnt_want_write_file()
404 		return mnt_clone_write(file->f_path.mnt);  in __mnt_want_write_file()
434 void __mnt_drop_write(struct vfsmount *mnt)  in __mnt_drop_write()  argument
437 	mnt_dec_writers(real_mount(mnt));  in __mnt_drop_write()
449 void mnt_drop_write(struct vfsmount *mnt)  in mnt_drop_write()  argument
451 	__mnt_drop_write(mnt);  in mnt_drop_write()
452 	sb_end_write(mnt->mnt_sb);  in mnt_drop_write()
458 	__mnt_drop_write(file->f_path.mnt);  in __mnt_drop_write_file()
468 static int mnt_make_readonly(struct mount *mnt)  in mnt_make_readonly()  argument
473 	mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;  in mnt_make_readonly()
496 	if (mnt_get_writers(mnt) > 0)  in mnt_make_readonly()
499 		mnt->mnt.mnt_flags |= MNT_READONLY;  in mnt_make_readonly()
505 	mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;  in mnt_make_readonly()
510 static void __mnt_unmake_readonly(struct mount *mnt)  in __mnt_unmake_readonly()  argument
513 	mnt->mnt.mnt_flags &= ~MNT_READONLY;  in __mnt_unmake_readonly()
519 	struct mount *mnt;  in sb_prepare_remount_readonly()  local
527 	list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {  in sb_prepare_remount_readonly()
528 		if (!(mnt->mnt.mnt_flags & MNT_READONLY)) {  in sb_prepare_remount_readonly()
529 			mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;  in sb_prepare_remount_readonly()
531 			if (mnt_get_writers(mnt) > 0) {  in sb_prepare_remount_readonly()
544 	list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {  in sb_prepare_remount_readonly()
545 		if (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)  in sb_prepare_remount_readonly()
546 			mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;  in sb_prepare_remount_readonly()
553 static void free_vfsmnt(struct mount *mnt)  in free_vfsmnt()  argument
555 	kfree_const(mnt->mnt_devname);  in free_vfsmnt()
557 	free_percpu(mnt->mnt_pcp);  in free_vfsmnt()
559 	kmem_cache_free(mnt_cache, mnt);  in free_vfsmnt()
570 	struct mount *mnt;  in __legitimize_mnt()  local
575 	mnt = real_mount(bastard);  in __legitimize_mnt()
576 	mnt_add_count(mnt, 1);  in __legitimize_mnt()
581 		mnt_add_count(mnt, -1);  in __legitimize_mnt()
586 		mnt_add_count(mnt, -1);  in __legitimize_mnt()
613 struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry)  in __lookup_mnt()  argument
615 	struct hlist_head *head = m_hash(mnt, dentry);  in __lookup_mnt()
619 		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry)  in __lookup_mnt()
649 		child_mnt = __lookup_mnt(path->mnt, path->dentry);  in lookup_mnt()
650 		m = child_mnt ? &child_mnt->mnt : NULL;  in lookup_mnt()
674 	struct mount *mnt;  in __is_local_mountpoint()  local
681 	list_for_each_entry(mnt, &ns->list, mnt_list) {  in __is_local_mountpoint()
682 		is_covered = (mnt->mnt_mountpoint == dentry);  in __is_local_mountpoint()
768 static inline int check_mnt(struct mount *mnt)  in check_mnt()  argument
770 	return mnt->mnt_ns == current->nsproxy->mnt_ns;  in check_mnt()
798 static void unhash_mnt(struct mount *mnt)  in unhash_mnt()  argument
800 	mnt->mnt_parent = mnt;  in unhash_mnt()
801 	mnt->mnt_mountpoint = mnt->mnt.mnt_root;  in unhash_mnt()
802 	list_del_init(&mnt->mnt_child);  in unhash_mnt()
803 	hlist_del_init_rcu(&mnt->mnt_hash);  in unhash_mnt()
804 	hlist_del_init(&mnt->mnt_mp_list);  in unhash_mnt()
805 	put_mountpoint(mnt->mnt_mp);  in unhash_mnt()
806 	mnt->mnt_mp = NULL;  in unhash_mnt()
812 static void detach_mnt(struct mount *mnt, struct path *old_path)  in detach_mnt()  argument
814 	old_path->dentry = mnt->mnt_mountpoint;  in detach_mnt()
815 	old_path->mnt = &mnt->mnt_parent->mnt;  in detach_mnt()
816 	unhash_mnt(mnt);  in detach_mnt()
822 static void umount_mnt(struct mount *mnt)  in umount_mnt()  argument
825 	mnt->mnt_ex_mountpoint = mnt->mnt_mountpoint;  in umount_mnt()
826 	unhash_mnt(mnt);  in umount_mnt()
832 void mnt_set_mountpoint(struct mount *mnt,  in mnt_set_mountpoint()  argument
837 	mnt_add_count(mnt, 1);	/* essentially, that's mntget */  in mnt_set_mountpoint()
839 	child_mnt->mnt_parent = mnt;  in mnt_set_mountpoint()
844 static void __attach_mnt(struct mount *mnt, struct mount *parent)  in __attach_mnt()  argument
846 	hlist_add_head_rcu(&mnt->mnt_hash,  in __attach_mnt()
847 			   m_hash(&parent->mnt, mnt->mnt_mountpoint));  in __attach_mnt()
848 	list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);  in __attach_mnt()
854 static void attach_mnt(struct mount *mnt,  in attach_mnt()  argument
858 	mnt_set_mountpoint(parent, mp, mnt);  in attach_mnt()
859 	__attach_mnt(mnt, parent);  in attach_mnt()
862 void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *mnt)  in mnt_change_mountpoint()  argument
864 	struct mountpoint *old_mp = mnt->mnt_mp;  in mnt_change_mountpoint()
865 	struct dentry *old_mountpoint = mnt->mnt_mountpoint;  in mnt_change_mountpoint()
866 	struct mount *old_parent = mnt->mnt_parent;  in mnt_change_mountpoint()
868 	list_del_init(&mnt->mnt_child);  in mnt_change_mountpoint()
869 	hlist_del_init(&mnt->mnt_mp_list);  in mnt_change_mountpoint()
870 	hlist_del_init_rcu(&mnt->mnt_hash);  in mnt_change_mountpoint()
872 	attach_mnt(mnt, parent, mp);  in mnt_change_mountpoint()
897 static void commit_tree(struct mount *mnt)  in commit_tree()  argument
899 	struct mount *parent = mnt->mnt_parent;  in commit_tree()
904 	BUG_ON(parent == mnt);  in commit_tree()
906 	list_add_tail(&head, &mnt->mnt_list);  in commit_tree()
915 	__attach_mnt(mnt, parent);  in commit_tree()
948 	struct mount *mnt;  in vfs_kern_mount()  local
954 	mnt = alloc_vfsmnt(name);  in vfs_kern_mount()
955 	if (!mnt)  in vfs_kern_mount()
959 		mnt->mnt.mnt_flags = MNT_INTERNAL;  in vfs_kern_mount()
963 		mnt_free_id(mnt);  in vfs_kern_mount()
964 		free_vfsmnt(mnt);  in vfs_kern_mount()
968 	mnt->mnt.mnt_root = root;  in vfs_kern_mount()
969 	mnt->mnt.mnt_sb = root->d_sb;  in vfs_kern_mount()
970 	mnt->mnt_mountpoint = mnt->mnt.mnt_root;  in vfs_kern_mount()
971 	mnt->mnt_parent = mnt;  in vfs_kern_mount()
973 	list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);  in vfs_kern_mount()
975 	return &mnt->mnt;  in vfs_kern_mount()
997 	struct super_block *sb = old->mnt.mnt_sb;  in clone_mnt()
998 	struct mount *mnt;  in clone_mnt()  local
1001 	mnt = alloc_vfsmnt(old->mnt_devname);  in clone_mnt()
1002 	if (!mnt)  in clone_mnt()
1006 		mnt->mnt_group_id = 0; /* not a peer of original */  in clone_mnt()
1008 		mnt->mnt_group_id = old->mnt_group_id;  in clone_mnt()
1010 	if ((flag & CL_MAKE_SHARED) && !mnt->mnt_group_id) {  in clone_mnt()
1011 		err = mnt_alloc_group_id(mnt);  in clone_mnt()
1016 	mnt->mnt.mnt_flags = old->mnt.mnt_flags;  in clone_mnt()
1017 	mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL);  in clone_mnt()
1020 		mnt->mnt.mnt_flags |= MNT_LOCK_ATIME;  in clone_mnt()
1022 		if (mnt->mnt.mnt_flags & MNT_READONLY)  in clone_mnt()
1023 			mnt->mnt.mnt_flags |= MNT_LOCK_READONLY;  in clone_mnt()
1025 		if (mnt->mnt.mnt_flags & MNT_NODEV)  in clone_mnt()
1026 			mnt->mnt.mnt_flags |= MNT_LOCK_NODEV;  in clone_mnt()
1028 		if (mnt->mnt.mnt_flags & MNT_NOSUID)  in clone_mnt()
1029 			mnt->mnt.mnt_flags |= MNT_LOCK_NOSUID;  in clone_mnt()
1031 		if (mnt->mnt.mnt_flags & MNT_NOEXEC)  in clone_mnt()
1032 			mnt->mnt.mnt_flags |= MNT_LOCK_NOEXEC;  in clone_mnt()
1038 		mnt->mnt.mnt_flags |= MNT_LOCKED;  in clone_mnt()
1041 	mnt->mnt.mnt_sb = sb;  in clone_mnt()
1042 	mnt->mnt.mnt_root = dget(root);  in clone_mnt()
1043 	mnt->mnt_mountpoint = mnt->mnt.mnt_root;  in clone_mnt()
1044 	mnt->mnt_parent = mnt;  in clone_mnt()
1046 	list_add_tail(&mnt->mnt_instance, &sb->s_mounts);  in clone_mnt()
1051 		list_add(&mnt->mnt_slave, &old->mnt_slave_list);  in clone_mnt()
1052 		mnt->mnt_master = old;  in clone_mnt()
1053 		CLEAR_MNT_SHARED(mnt);  in clone_mnt()
1056 			list_add(&mnt->mnt_share, &old->mnt_share);  in clone_mnt()
1058 			list_add(&mnt->mnt_slave, &old->mnt_slave);  in clone_mnt()
1059 		mnt->mnt_master = old->mnt_master;  in clone_mnt()
1061 		CLEAR_MNT_SHARED(mnt);  in clone_mnt()
1064 		set_mnt_shared(mnt);  in clone_mnt()
1070 			list_add(&mnt->mnt_expire, &old->mnt_expire);  in clone_mnt()
1073 	return mnt;  in clone_mnt()
1076 	mnt_free_id(mnt);  in clone_mnt()
1077 	free_vfsmnt(mnt);  in clone_mnt()
1081 static void cleanup_mnt(struct mount *mnt)  in cleanup_mnt()  argument
1093 	WARN_ON(mnt_get_writers(mnt));  in cleanup_mnt()
1094 	if (unlikely(mnt->mnt_pins.first))  in cleanup_mnt()
1095 		mnt_pin_kill(mnt);  in cleanup_mnt()
1096 	fsnotify_vfsmount_delete(&mnt->mnt);  in cleanup_mnt()
1097 	dput(mnt->mnt.mnt_root);  in cleanup_mnt()
1098 	deactivate_super(mnt->mnt.mnt_sb);  in cleanup_mnt()
1099 	mnt_free_id(mnt);  in cleanup_mnt()
1100 	call_rcu(&mnt->mnt_rcu, delayed_free_vfsmnt);  in cleanup_mnt()
1119 static void mntput_no_expire(struct mount *mnt)  in mntput_no_expire()  argument
1122 	if (likely(READ_ONCE(mnt->mnt_ns))) {  in mntput_no_expire()
1132 		mnt_add_count(mnt, -1);  in mntput_no_expire()
1142 	mnt_add_count(mnt, -1);  in mntput_no_expire()
1143 	if (mnt_get_count(mnt)) {  in mntput_no_expire()
1148 	if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) {  in mntput_no_expire()
1153 	mnt->mnt.mnt_flags |= MNT_DOOMED;  in mntput_no_expire()
1156 	list_del(&mnt->mnt_instance);  in mntput_no_expire()
1158 	if (unlikely(!list_empty(&mnt->mnt_mounts))) {  in mntput_no_expire()
1160 		list_for_each_entry_safe(p, tmp, &mnt->mnt_mounts,  mnt_child) {  in mntput_no_expire()
1166 	if (likely(!(mnt->mnt.mnt_flags & MNT_INTERNAL))) {  in mntput_no_expire()
1169 			init_task_work(&mnt->mnt_rcu, __cleanup_mnt);  in mntput_no_expire()
1170 			if (!task_work_add(task, &mnt->mnt_rcu, true))  in mntput_no_expire()
1173 		if (llist_add(&mnt->mnt_llist, &delayed_mntput_list))  in mntput_no_expire()
1177 	cleanup_mnt(mnt);  in mntput_no_expire()
1180 void mntput(struct vfsmount *mnt)  in mntput()  argument
1182 	if (mnt) {  in mntput()
1183 		struct mount *m = real_mount(mnt);  in mntput()
1192 struct vfsmount *mntget(struct vfsmount *mnt)  in mntget()  argument
1194 	if (mnt)  in mntget()
1195 		mnt_add_count(real_mount(mnt), 1);  in mntget()
1196 	return mnt;  in mntget()
1232 	p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE);  in mnt_clone_internal()
1235 	p->mnt.mnt_flags |= MNT_INTERNAL;  in mnt_clone_internal()
1236 	return &p->mnt;  in mnt_clone_internal()
1280 	return p->show(m, &r->mnt);  in m_show()
1301 	struct mount *mnt = real_mount(m);  in may_umount_tree()  local
1309 	for (p = mnt; p; p = next_mnt(p, mnt)) {  in may_umount_tree()
1336 int may_umount(struct vfsmount *mnt)  in may_umount()  argument
1341 	if (propagate_mount_busy(real_mount(mnt), 2))  in may_umount()
1379 static bool disconnect_mount(struct mount *mnt, enum umount_tree_flags how)  in disconnect_mount()  argument
1386 	if (!mnt_has_parent(mnt))  in disconnect_mount()
1393 	if (!(mnt->mnt_parent->mnt.mnt_flags & MNT_UMOUNT))  in disconnect_mount()
1401 	if (IS_MNT_LOCKED(mnt))  in disconnect_mount()
1412 static void umount_tree(struct mount *mnt, enum umount_tree_flags how)  in umount_tree()  argument
1418 		propagate_mount_unlock(mnt);  in umount_tree()
1421 	for (p = mnt; p; p = next_mnt(p, mnt)) {  in umount_tree()
1422 		p->mnt.mnt_flags |= MNT_UMOUNT;  in umount_tree()
1448 			p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;  in umount_tree()
1452 		pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt,  in umount_tree()
1467 static void shrink_submounts(struct mount *mnt);
1469 static int do_umount(struct mount *mnt, int flags)  in do_umount()  argument
1471 	struct super_block *sb = mnt->mnt.mnt_sb;  in do_umount()
1474 	retval = security_sb_umount(&mnt->mnt, flags);  in do_umount()
1485 		if (&mnt->mnt == current->fs->root.mnt ||  in do_umount()
1494 		if (mnt_get_count(mnt) != 2) {  in do_umount()
1500 		if (!xchg(&mnt->mnt_expiry_mark, 1))  in do_umount()
1527 	if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {  in do_umount()
1546 		if (!list_empty(&mnt->mnt_list))  in do_umount()
1547 			umount_tree(mnt, UMOUNT_PROPAGATE);  in do_umount()
1550 		shrink_submounts(mnt);  in do_umount()
1552 		if (!propagate_mount_busy(mnt, 2)) {  in do_umount()
1553 			if (!list_empty(&mnt->mnt_list))  in do_umount()
1554 				umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);  in do_umount()
1576 	struct mount *mnt;  in __detach_mounts()  local
1586 		mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);  in __detach_mounts()
1587 		if (mnt->mnt.mnt_flags & MNT_UMOUNT) {  in __detach_mounts()
1588 			hlist_add_head(&mnt->mnt_umount.s_list, &unmounted);  in __detach_mounts()
1589 			umount_mnt(mnt);  in __detach_mounts()
1591 		else umount_tree(mnt, UMOUNT_CONNECTED);  in __detach_mounts()
1626 	struct mount *mnt;  in ksys_umount()  local
1642 	mnt = real_mount(path.mnt);  in ksys_umount()
1644 	if (path.dentry != path.mnt->mnt_root)  in ksys_umount()
1646 	if (!check_mnt(mnt))  in ksys_umount()
1648 	if (mnt->mnt.mnt_flags & MNT_LOCKED)  in ksys_umount()
1654 	retval = do_umount(mnt, flags);  in ksys_umount()
1658 	mntput_no_expire(mnt);  in ksys_umount()
1705 struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,  in copy_tree()  argument
1710 	if (!(flag & CL_COPY_UNBINDABLE) && IS_MNT_UNBINDABLE(mnt))  in copy_tree()
1716 	res = q = clone_mnt(mnt, dentry, flag);  in copy_tree()
1720 	q->mnt_mountpoint = mnt->mnt_mountpoint;  in copy_tree()
1722 	p = mnt;  in copy_tree()
1723 	list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {  in copy_tree()
1735 			    is_mnt_ns_file(s->mnt.mnt_root)) {  in copy_tree()
1745 			q = clone_mnt(p, p->mnt.mnt_root, flag);  in copy_tree()
1770 	if (!check_mnt(real_mount(path->mnt)))  in collect_mounts()
1773 		tree = copy_tree(real_mount(path->mnt), path->dentry,  in collect_mounts()
1778 	return &tree->mnt;  in collect_mounts()
1781 void drop_collected_mounts(struct vfsmount *mnt)  in drop_collected_mounts()  argument
1785 	umount_tree(real_mount(mnt), UMOUNT_SYNC);  in drop_collected_mounts()
1801 	struct mount *old_mnt = real_mount(path->mnt);  in clone_private_mount()
1811 	return &new_mnt->mnt;  in clone_private_mount()
1818 	struct mount *mnt;  in iterate_mounts()  local
1822 	list_for_each_entry(mnt, &real_mount(root)->mnt_list, mnt_list) {  in iterate_mounts()
1823 		res = f(&mnt->mnt, arg);  in iterate_mounts()
1830 static void cleanup_group_ids(struct mount *mnt, struct mount *end)  in cleanup_group_ids()  argument
1834 	for (p = mnt; p != end; p = next_mnt(p, mnt)) {  in cleanup_group_ids()
1840 static int invent_group_ids(struct mount *mnt, bool recurse)  in invent_group_ids()  argument
1844 	for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) {  in invent_group_ids()
1848 				cleanup_group_ids(mnt, p);  in invent_group_ids()
1857 int count_mounts(struct mnt_namespace *ns, struct mount *mnt)  in count_mounts()  argument
1863 	for (p = mnt; p; p = next_mnt(p, mnt))  in count_mounts()
1957 	smp = get_mountpoint(source_mnt->mnt.mnt_root);  in attach_recursive_mnt()
1993 		q = __lookup_mnt(&child->mnt_parent->mnt,  in attach_recursive_mnt()
2024 	struct vfsmount *mnt;  in lock_mount()  local
2033 	mnt = lookup_mnt(path);  in lock_mount()
2034 	if (likely(!mnt)) {  in lock_mount()
2046 	path->mnt = mnt;  in lock_mount()
2047 	dentry = path->dentry = dget(mnt->mnt_root);  in lock_mount()
2063 static int graft_tree(struct mount *mnt, struct mount *p, struct mountpoint *mp)  in graft_tree()  argument
2065 	if (mnt->mnt.mnt_sb->s_flags & SB_NOUSER)  in graft_tree()
2069 	      d_is_dir(mnt->mnt.mnt_root))  in graft_tree()
2072 	return attach_recursive_mnt(mnt, p, mp, NULL);  in graft_tree()
2098 	struct mount *mnt = real_mount(path->mnt);  in do_change_type()  local
2103 	if (path->dentry != path->mnt->mnt_root)  in do_change_type()
2112 		err = invent_group_ids(mnt, recurse);  in do_change_type()
2118 	for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL))  in do_change_type()
2127 static bool has_locked_children(struct mount *mnt, struct dentry *dentry)  in has_locked_children()  argument
2130 	list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) {  in has_locked_children()
2134 		if (child->mnt.mnt_flags & MNT_LOCKED)  in has_locked_children()
2147 	struct mount *mnt = NULL, *old, *parent;  in do_loopback()  local
2165 	old = real_mount(old_path.mnt);  in do_loopback()
2166 	parent = real_mount(path->mnt);  in do_loopback()
2182 		mnt = copy_tree(old, old_path.dentry, CL_COPY_MNT_NS_FILE);  in do_loopback()
2184 		mnt = clone_mnt(old, old_path.dentry, 0);  in do_loopback()
2186 	if (IS_ERR(mnt)) {  in do_loopback()
2187 		err = PTR_ERR(mnt);  in do_loopback()
2191 	mnt->mnt.mnt_flags &= ~MNT_LOCKED;  in do_loopback()
2193 	err = graft_tree(mnt, parent, mp);  in do_loopback()
2196 		umount_tree(mnt, UMOUNT_SYNC);  in do_loopback()
2206 static int change_mount_flags(struct vfsmount *mnt, int ms_flags)  in change_mount_flags()  argument
2213 	if (readonly_request == __mnt_is_readonly(mnt))  in change_mount_flags()
2217 		error = mnt_make_readonly(real_mount(mnt));  in change_mount_flags()
2219 		__mnt_unmake_readonly(real_mount(mnt));  in change_mount_flags()
2232 	struct super_block *sb = path->mnt->mnt_sb;  in do_remount()
2233 	struct mount *mnt = real_mount(path->mnt);  in do_remount()  local
2235 	if (!check_mnt(mnt))  in do_remount()
2238 	if (path->dentry != path->mnt->mnt_root)  in do_remount()
2247 	if ((mnt->mnt.mnt_flags & MNT_LOCK_READONLY) &&  in do_remount()
2251 	if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) &&  in do_remount()
2255 	if ((mnt->mnt.mnt_flags & MNT_LOCK_NOSUID) &&  in do_remount()
2259 	if ((mnt->mnt.mnt_flags & MNT_LOCK_NOEXEC) &&  in do_remount()
2263 	if ((mnt->mnt.mnt_flags & MNT_LOCK_ATIME) &&  in do_remount()
2264 	    ((mnt->mnt.mnt_flags & MNT_ATIME_MASK) != (mnt_flags & MNT_ATIME_MASK))) {  in do_remount()
2274 		err = change_mount_flags(path->mnt, ms_flags);  in do_remount()
2281 		mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK;  in do_remount()
2282 		mnt->mnt.mnt_flags = mnt_flags;  in do_remount()
2283 		touch_mnt_namespace(mnt->mnt_ns);  in do_remount()
2290 static inline int tree_contains_unbindable(struct mount *mnt)  in tree_contains_unbindable()  argument
2293 	for (p = mnt; p; p = next_mnt(p, mnt)) {  in tree_contains_unbindable()
2318 	old = real_mount(old_path.mnt);  in do_move_mount()
2319 	p = real_mount(path->mnt);  in do_move_mount()
2325 	if (old->mnt.mnt_flags & MNT_LOCKED)  in do_move_mount()
2329 	if (old_path.dentry != old_path.mnt->mnt_root)  in do_move_mount()
2354 	err = attach_recursive_mnt(old, real_mount(path->mnt), mp, &parent_path);  in do_move_mount()
2370 static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)  in fs_set_subtype()  argument
2382 	mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);  in fs_set_subtype()
2384 	if (!mnt->mnt_sb->s_subtype)  in fs_set_subtype()
2386 	return mnt;  in fs_set_subtype()
2389 	mntput(mnt);  in fs_set_subtype()
2408 	parent = real_mount(path->mnt);  in do_add_mount()
2421 	if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb &&  in do_add_mount()
2422 	    path->mnt->mnt_root == path->dentry)  in do_add_mount()
2426 	if (d_is_symlink(newmnt->mnt.mnt_root))  in do_add_mount()
2429 	newmnt->mnt.mnt_flags = mnt_flags;  in do_add_mount()
2437 static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags);
2447 	struct vfsmount *mnt;  in do_new_mount()  local
2457 	mnt = vfs_kern_mount(type, sb_flags, name, data);  in do_new_mount()
2458 	if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&  in do_new_mount()
2459 	    !mnt->mnt_sb->s_subtype)  in do_new_mount()
2460 		mnt = fs_set_subtype(mnt, fstype);  in do_new_mount()
2463 	if (IS_ERR(mnt))  in do_new_mount()
2464 		return PTR_ERR(mnt);  in do_new_mount()
2466 	if (mount_too_revealing(mnt, &mnt_flags)) {  in do_new_mount()
2467 		mntput(mnt);  in do_new_mount()
2471 	err = do_add_mount(real_mount(mnt), path, mnt_flags);  in do_new_mount()
2473 		mntput(mnt);  in do_new_mount()
2479 	struct mount *mnt = real_mount(m);  in finish_automount()  local
2484 	BUG_ON(mnt_get_count(mnt) < 2);  in finish_automount()
2486 	if (m->mnt_sb == path->mnt->mnt_sb &&  in finish_automount()
2492 	err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE);  in finish_automount()
2497 	if (!list_empty(&mnt->mnt_expire)) {  in finish_automount()
2499 		list_del_init(&mnt->mnt_expire);  in finish_automount()
2512 void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list)  in mnt_set_expiry()  argument
2516 	list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list);  in mnt_set_expiry()
2529 	struct mount *mnt, *next;  in mark_mounts_for_expiry()  local
2544 	list_for_each_entry_safe(mnt, next, mounts, mnt_expire) {  in mark_mounts_for_expiry()
2545 		if (!xchg(&mnt->mnt_expiry_mark, 1) ||  in mark_mounts_for_expiry()
2546 			propagate_mount_busy(mnt, 1))  in mark_mounts_for_expiry()
2548 		list_move(&mnt->mnt_expire, &graveyard);  in mark_mounts_for_expiry()
2551 		mnt = list_first_entry(&graveyard, struct mount, mnt_expire);  in mark_mounts_for_expiry()
2552 		touch_mnt_namespace(mnt->mnt_ns);  in mark_mounts_for_expiry()
2553 		umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);  in mark_mounts_for_expiry()
2578 		struct mount *mnt = list_entry(tmp, struct mount, mnt_child);  in select_submounts()  local
2581 		if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE))  in select_submounts()
2586 		if (!list_empty(&mnt->mnt_mounts)) {  in select_submounts()
2587 			this_parent = mnt;  in select_submounts()
2591 		if (!propagate_mount_busy(mnt, 1)) {  in select_submounts()
2592 			list_move_tail(&mnt->mnt_expire, graveyard);  in select_submounts()
2613 static void shrink_submounts(struct mount *mnt)  in shrink_submounts()  argument
2619 	while (select_submounts(mnt, &graveyard)) {  in shrink_submounts()
2765 		mnt_flags |= path.mnt->mnt_flags & MNT_ATIME_MASK;  in do_mount()
2885 	new = copy_tree(old, old->mnt.mnt_root, copy_flags);  in copy_mnt_ns()
2905 			if (&p->mnt == new_fs->root.mnt) {  in copy_mnt_ns()
2906 				new_fs->root.mnt = mntget(&q->mnt);  in copy_mnt_ns()
2907 				rootmnt = &p->mnt;  in copy_mnt_ns()
2909 			if (&p->mnt == new_fs->pwd.mnt) {  in copy_mnt_ns()
2910 				new_fs->pwd.mnt = mntget(&q->mnt);  in copy_mnt_ns()
2911 				pwdmnt = &p->mnt;  in copy_mnt_ns()
2918 		while (p->mnt.mnt_root != q->mnt.mnt_root)  in copy_mnt_ns()
2939 		struct mount *mnt = real_mount(m);  in create_mnt_ns()  local
2940 		mnt->mnt_ns = new_ns;  in create_mnt_ns()
2941 		new_ns->root = mnt;  in create_mnt_ns()
2943 		list_add(&mnt->mnt_list, &new_ns->list);  in create_mnt_ns()
2950 struct dentry *mount_subtree(struct vfsmount *mnt, const char *name)  in mount_subtree()  argument
2957 	ns = create_mnt_ns(mnt);  in mount_subtree()
2961 	err = vfs_path_lookup(mnt->mnt_root, mnt,  in mount_subtree()
2970 	s = path.mnt->mnt_sb;  in mount_subtree()
2972 	mntput(path.mnt);  in mount_subtree()
3025 bool is_path_reachable(struct mount *mnt, struct dentry *dentry,  in is_path_reachable()  argument
3028 	while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) {  in is_path_reachable()
3029 		dentry = mnt->mnt_mountpoint;  in is_path_reachable()
3030 		mnt = mnt->mnt_parent;  in is_path_reachable()
3032 	return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);  in is_path_reachable()
3039 	res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);  in path_is_under()
3100 	new_mnt = real_mount(new.mnt);  in SYSCALL_DEFINE2()
3101 	root_mnt = real_mount(root.mnt);  in SYSCALL_DEFINE2()
3102 	old_mnt = real_mount(old.mnt);  in SYSCALL_DEFINE2()
3109 	if (new_mnt->mnt.mnt_flags & MNT_LOCKED)  in SYSCALL_DEFINE2()
3118 	if (root.mnt->mnt_root != root.dentry)  in SYSCALL_DEFINE2()
3123 	if (new.mnt->mnt_root != new.dentry)  in SYSCALL_DEFINE2()
3137 	if (root_mnt->mnt.mnt_flags & MNT_LOCKED) {  in SYSCALL_DEFINE2()
3138 		new_mnt->mnt.mnt_flags |= MNT_LOCKED;  in SYSCALL_DEFINE2()
3139 		root_mnt->mnt.mnt_flags &= ~MNT_LOCKED;  in SYSCALL_DEFINE2()
3144 	attach_mnt(new_mnt, real_mount(root_parent.mnt), root_mp);  in SYSCALL_DEFINE2()
3170 	struct vfsmount *mnt;  in init_mount_tree()  local
3178 	mnt = vfs_kern_mount(type, 0, "rootfs", NULL);  in init_mount_tree()
3180 	if (IS_ERR(mnt))  in init_mount_tree()
3183 	ns = create_mnt_ns(mnt);  in init_mount_tree()
3190 	root.mnt = mnt;  in init_mount_tree()
3191 	root.dentry = mnt->mnt_root;  in init_mount_tree()
3192 	mnt->mnt_flags |= MNT_LOCKED;  in init_mount_tree()
3236 	drop_collected_mounts(&ns->root->mnt);  in put_mnt_ns()
3242 	struct vfsmount *mnt;  in kern_mount_data()  local
3243 	mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, data);  in kern_mount_data()
3244 	if (!IS_ERR(mnt)) {  in kern_mount_data()
3249 		real_mount(mnt)->mnt_ns = MNT_NS_INTERNAL;  in kern_mount_data()
3251 	return mnt;  in kern_mount_data()
3255 void kern_unmount(struct vfsmount *mnt)  in kern_unmount()  argument
3258 	if (!IS_ERR_OR_NULL(mnt)) {  in kern_unmount()
3259 		real_mount(mnt)->mnt_ns = NULL;  in kern_unmount()
3261 		mntput(mnt);  in kern_unmount()
3266 bool our_mnt(struct vfsmount *mnt)  in our_mnt()  argument
3268 	return check_mnt(real_mount(mnt));  in our_mnt()
3279 	ns_root.mnt = &current->nsproxy->mnt_ns->root->mnt;  in current_chrooted()
3280 	ns_root.dentry = ns_root.mnt->mnt_root;  in current_chrooted()
3299 	struct mount *mnt;  in mnt_already_visible()  local
3303 	list_for_each_entry(mnt, &ns->list, mnt_list) {  in mnt_already_visible()
3307 		if (mnt->mnt.mnt_sb->s_type != new->mnt_sb->s_type)  in mnt_already_visible()
3313 		if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root)  in mnt_already_visible()
3317 		mnt_flags = mnt->mnt.mnt_flags;  in mnt_already_visible()
3320 		if (sb_rdonly(mnt->mnt.mnt_sb))  in mnt_already_visible()
3337 		list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) {  in mnt_already_visible()
3340 			if (!(child->mnt.mnt_flags & MNT_LOCKED))  in mnt_already_visible()
3358 static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags)  in mount_too_revealing()  argument
3368 	s_iflags = mnt->mnt_sb->s_iflags;  in mount_too_revealing()
3378 	return !mnt_already_visible(ns, mnt, new_mnt_flags);  in mount_too_revealing()
3381 bool mnt_may_suid(struct vfsmount *mnt)  in mnt_may_suid()  argument
3390 	return !(mnt->mnt_flags & MNT_NOSUID) && check_mnt(real_mount(mnt)) &&  in mnt_may_suid()
3391 	       current_in_userns(mnt->mnt_sb->s_user_ns);  in mnt_may_suid()
3435 	err = vfs_path_lookup(mnt_ns->root->mnt.mnt_root, &mnt_ns->root->mnt,  in mntns_install()