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