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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
8struct mnt_namespace {
9 atomic_t count;
10 struct ns_common ns;
11 struct mount * root;
12 struct list_head list;
13 struct user_namespace *user_ns;
14 struct ucounts *ucounts;
15 u64 seq; /* Sequence number to prevent loops */
16 wait_queue_head_t poll;
17 u64 event;
18 unsigned int mounts; /* # of mounts in the namespace */
19 unsigned int pending_mounts;
20} __randomize_layout;
21
22struct mnt_pcp {
23 int mnt_count;
24 int mnt_writers;
25};
26
27struct mountpoint {
28 struct hlist_node m_hash;
29 struct dentry *m_dentry;
30 struct hlist_head m_list;
31 int m_count;
32};
33
34struct mount {
35 struct hlist_node mnt_hash;
36 struct mount *mnt_parent;
37 struct dentry *mnt_mountpoint;
38 struct vfsmount mnt;
39 union {
40 struct rcu_head mnt_rcu;
41 struct llist_node mnt_llist;
42 };
43#ifdef CONFIG_SMP
44 struct mnt_pcp __percpu *mnt_pcp;
45#else
46 int mnt_count;
47 int mnt_writers;
48#endif
49 struct list_head mnt_mounts; /* list of children, anchored here */
50 struct list_head mnt_child; /* and going through their mnt_child */
51 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
52 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
53 struct list_head mnt_list;
54 struct list_head mnt_expire; /* link in fs-specific expiry list */
55 struct list_head mnt_share; /* circular list of shared mounts */
56 struct list_head mnt_slave_list;/* list of slave mounts */
57 struct list_head mnt_slave; /* slave list entry */
58 struct mount *mnt_master; /* slave is on master->mnt_slave_list */
59 struct mnt_namespace *mnt_ns; /* containing namespace */
60 struct mountpoint *mnt_mp; /* where is it mounted */
61 union {
62 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
63 struct hlist_node mnt_umount;
64 };
65 struct list_head mnt_umounting; /* list entry for umount propagation */
66#ifdef CONFIG_FSNOTIFY
67 struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
68 __u32 mnt_fsnotify_mask;
69#endif
70 int mnt_id; /* mount identifier */
71 int mnt_group_id; /* peer group identifier */
72 int mnt_expiry_mark; /* true if marked for expiry */
73 struct hlist_head mnt_pins;
74 struct hlist_head mnt_stuck_children;
75} __randomize_layout;
76
77#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
78
79static inline struct mount *real_mount(struct vfsmount *mnt)
80{
81 return container_of(mnt, struct mount, mnt);
82}
83
84static inline int mnt_has_parent(struct mount *mnt)
85{
86 return mnt != mnt->mnt_parent;
87}
88
89static inline int is_mounted(struct vfsmount *mnt)
90{
91 /* neither detached nor internal? */
92 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
93}
94
95extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
96
97extern int __legitimize_mnt(struct vfsmount *, unsigned);
98extern bool legitimize_mnt(struct vfsmount *, unsigned);
99
100static inline bool __path_is_mountpoint(const struct path *path)
101{
102 struct mount *m = __lookup_mnt(path->mnt, path->dentry);
103 return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
104}
105
106extern void __detach_mounts(struct dentry *dentry);
107
108static inline void detach_mounts(struct dentry *dentry)
109{
110 if (!d_mountpoint(dentry))
111 return;
112 __detach_mounts(dentry);
113}
114
115static inline void get_mnt_ns(struct mnt_namespace *ns)
116{
117 atomic_inc(&ns->count);
118}
119
120extern seqlock_t mount_lock;
121
122static inline void lock_mount_hash(void)
123{
124 write_seqlock(&mount_lock);
125}
126
127static inline void unlock_mount_hash(void)
128{
129 write_sequnlock(&mount_lock);
130}
131
132struct proc_mounts {
133 struct mnt_namespace *ns;
134 struct path root;
135 int (*show)(struct seq_file *, struct vfsmount *);
136 void *cached_mount;
137 u64 cached_event;
138 loff_t cached_index;
139};
140
141extern const struct seq_operations mounts_op;
142
143extern bool __is_local_mountpoint(struct dentry *dentry);
144static inline bool is_local_mountpoint(struct dentry *dentry)
145{
146 if (!d_mountpoint(dentry))
147 return false;
148
149 return __is_local_mountpoint(dentry);
150}
151
152static inline bool is_anon_ns(struct mnt_namespace *ns)
153{
154 return ns->seq == 0;
155}
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
8struct 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 struct rb_node mnt_ns_tree_node; /* node in the mnt_ns_tree */
20 refcount_t passive; /* number references not pinning @mounts */
21} __randomize_layout;
22
23struct mnt_pcp {
24 int mnt_count;
25 int mnt_writers;
26};
27
28struct mountpoint {
29 struct hlist_node m_hash;
30 struct dentry *m_dentry;
31 struct hlist_head m_list;
32 int m_count;
33};
34
35struct mount {
36 struct hlist_node mnt_hash;
37 struct mount *mnt_parent;
38 struct dentry *mnt_mountpoint;
39 struct vfsmount mnt;
40 union {
41 struct rb_node mnt_node; /* node in the ns->mounts rbtree */
42 struct rcu_head mnt_rcu;
43 struct llist_node mnt_llist;
44 };
45#ifdef CONFIG_SMP
46 struct mnt_pcp __percpu *mnt_pcp;
47#else
48 int mnt_count;
49 int mnt_writers;
50#endif
51 struct list_head mnt_mounts; /* list of children, anchored here */
52 struct list_head mnt_child; /* and going through their mnt_child */
53 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
54 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
55 struct list_head mnt_list;
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
82static inline struct mount *real_mount(struct vfsmount *mnt)
83{
84 return container_of(mnt, struct mount, mnt);
85}
86
87static inline int mnt_has_parent(struct mount *mnt)
88{
89 return mnt != mnt->mnt_parent;
90}
91
92static inline int is_mounted(struct vfsmount *mnt)
93{
94 /* neither detached nor internal? */
95 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
96}
97
98extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
99
100extern int __legitimize_mnt(struct vfsmount *, unsigned);
101
102static 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
108extern void __detach_mounts(struct dentry *dentry);
109
110static inline void detach_mounts(struct dentry *dentry)
111{
112 if (!d_mountpoint(dentry))
113 return;
114 __detach_mounts(dentry);
115}
116
117static inline void get_mnt_ns(struct mnt_namespace *ns)
118{
119 refcount_inc(&ns->ns.count);
120}
121
122extern seqlock_t mount_lock;
123
124struct proc_mounts {
125 struct mnt_namespace *ns;
126 struct path root;
127 int (*show)(struct seq_file *, struct vfsmount *);
128};
129
130extern const struct seq_operations mounts_op;
131
132extern bool __is_local_mountpoint(struct dentry *dentry);
133static 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
141static inline bool is_anon_ns(struct mnt_namespace *ns)
142{
143 return ns->seq == 0;
144}
145
146static inline bool mnt_ns_attached(const struct mount *mnt)
147{
148 return !RB_EMPTY_NODE(&mnt->mnt_node);
149}
150
151static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list)
152{
153 WARN_ON(!mnt_ns_attached(mnt));
154 rb_erase(&mnt->mnt_node, &mnt->mnt_ns->mounts);
155 RB_CLEAR_NODE(&mnt->mnt_node);
156 list_add_tail(&mnt->mnt_list, dt_list);
157}
158
159bool has_locked_children(struct mount *mnt, struct dentry *dentry);
160struct mnt_namespace *__lookup_next_mnt_ns(struct mnt_namespace *mnt_ns, bool previous);
161static inline struct mnt_namespace *lookup_next_mnt_ns(struct mnt_namespace *mntns)
162{
163 return __lookup_next_mnt_ns(mntns, false);
164}
165static inline struct mnt_namespace *lookup_prev_mnt_ns(struct mnt_namespace *mntns)
166{
167 return __lookup_next_mnt_ns(mntns, true);
168}
169static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
170{
171 return container_of(ns, struct mnt_namespace, ns);
172}