1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #include <linux/mount.h> |
3 | #include <linux/seq_file.h> |
4 | #include <linux/poll.h> |
5 | #include <linux/ns_common.h> |
6 | #include <linux/fs_pin.h> |
7 | |
8 | struct mnt_namespace { |
9 | struct ns_common ns; |
10 | struct mount * root; |
11 | struct rb_root mounts; /* Protected by namespace_sem */ |
12 | struct user_namespace *user_ns; |
13 | struct ucounts *ucounts; |
14 | u64 seq; /* Sequence number to prevent loops */ |
15 | wait_queue_head_t poll; |
16 | u64 event; |
17 | unsigned int nr_mounts; /* # of mounts in the namespace */ |
18 | unsigned int pending_mounts; |
19 | } __randomize_layout; |
20 | |
21 | struct mnt_pcp { |
22 | int mnt_count; |
23 | int mnt_writers; |
24 | }; |
25 | |
26 | struct mountpoint { |
27 | struct hlist_node m_hash; |
28 | struct dentry *m_dentry; |
29 | struct hlist_head m_list; |
30 | int m_count; |
31 | }; |
32 | |
33 | struct mount { |
34 | struct hlist_node mnt_hash; |
35 | struct mount *mnt_parent; |
36 | struct dentry *mnt_mountpoint; |
37 | struct vfsmount mnt; |
38 | union { |
39 | struct rcu_head mnt_rcu; |
40 | struct llist_node mnt_llist; |
41 | }; |
42 | #ifdef CONFIG_SMP |
43 | struct mnt_pcp __percpu *mnt_pcp; |
44 | #else |
45 | int mnt_count; |
46 | int mnt_writers; |
47 | #endif |
48 | struct list_head mnt_mounts; /* list of children, anchored here */ |
49 | struct list_head mnt_child; /* and going through their mnt_child */ |
50 | struct list_head mnt_instance; /* mount instance on sb->s_mounts */ |
51 | const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ |
52 | union { |
53 | struct rb_node mnt_node; /* Under ns->mounts */ |
54 | struct list_head mnt_list; |
55 | }; |
56 | struct list_head mnt_expire; /* link in fs-specific expiry list */ |
57 | struct list_head mnt_share; /* circular list of shared mounts */ |
58 | struct list_head mnt_slave_list;/* list of slave mounts */ |
59 | struct list_head mnt_slave; /* slave list entry */ |
60 | struct mount *mnt_master; /* slave is on master->mnt_slave_list */ |
61 | struct mnt_namespace *mnt_ns; /* containing namespace */ |
62 | struct mountpoint *mnt_mp; /* where is it mounted */ |
63 | union { |
64 | struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ |
65 | struct hlist_node mnt_umount; |
66 | }; |
67 | struct list_head mnt_umounting; /* list entry for umount propagation */ |
68 | #ifdef CONFIG_FSNOTIFY |
69 | struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks; |
70 | __u32 mnt_fsnotify_mask; |
71 | #endif |
72 | int mnt_id; /* mount identifier, reused */ |
73 | u64 mnt_id_unique; /* mount ID unique until reboot */ |
74 | int mnt_group_id; /* peer group identifier */ |
75 | int mnt_expiry_mark; /* true if marked for expiry */ |
76 | struct hlist_head mnt_pins; |
77 | struct hlist_head mnt_stuck_children; |
78 | } __randomize_layout; |
79 | |
80 | #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ |
81 | |
82 | static inline struct mount *real_mount(struct vfsmount *mnt) |
83 | { |
84 | return container_of(mnt, struct mount, mnt); |
85 | } |
86 | |
87 | static inline int mnt_has_parent(struct mount *mnt) |
88 | { |
89 | return mnt != mnt->mnt_parent; |
90 | } |
91 | |
92 | static inline int is_mounted(struct vfsmount *mnt) |
93 | { |
94 | /* neither detached nor internal? */ |
95 | return !IS_ERR_OR_NULL(ptr: real_mount(mnt)->mnt_ns); |
96 | } |
97 | |
98 | extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); |
99 | |
100 | extern int __legitimize_mnt(struct vfsmount *, unsigned); |
101 | |
102 | static inline bool __path_is_mountpoint(const struct path *path) |
103 | { |
104 | struct mount *m = __lookup_mnt(path->mnt, path->dentry); |
105 | return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT)); |
106 | } |
107 | |
108 | extern void __detach_mounts(struct dentry *dentry); |
109 | |
110 | static inline void detach_mounts(struct dentry *dentry) |
111 | { |
112 | if (!d_mountpoint(dentry)) |
113 | return; |
114 | __detach_mounts(dentry); |
115 | } |
116 | |
117 | static inline void get_mnt_ns(struct mnt_namespace *ns) |
118 | { |
119 | refcount_inc(r: &ns->ns.count); |
120 | } |
121 | |
122 | extern seqlock_t mount_lock; |
123 | |
124 | struct proc_mounts { |
125 | struct mnt_namespace *ns; |
126 | struct path root; |
127 | int (*show)(struct seq_file *, struct vfsmount *); |
128 | }; |
129 | |
130 | extern const struct seq_operations mounts_op; |
131 | |
132 | extern bool __is_local_mountpoint(struct dentry *dentry); |
133 | static inline bool is_local_mountpoint(struct dentry *dentry) |
134 | { |
135 | if (!d_mountpoint(dentry)) |
136 | return false; |
137 | |
138 | return __is_local_mountpoint(dentry); |
139 | } |
140 | |
141 | static inline bool is_anon_ns(struct mnt_namespace *ns) |
142 | { |
143 | return ns->seq == 0; |
144 | } |
145 | |
146 | static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list) |
147 | { |
148 | WARN_ON(!(mnt->mnt.mnt_flags & MNT_ONRB)); |
149 | mnt->mnt.mnt_flags &= ~MNT_ONRB; |
150 | rb_erase(&mnt->mnt_node, &mnt->mnt_ns->mounts); |
151 | list_add_tail(new: &mnt->mnt_list, head: dt_list); |
152 | } |
153 | |
154 | extern void mnt_cursor_del(struct mnt_namespace *ns, struct mount *cursor); |
155 | |