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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 /*
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
27struct mnt_pcp {
28 int mnt_count;
29 int mnt_writers;
30};
31
32struct mountpoint {
33 struct hlist_node m_hash;
34 struct dentry *m_dentry;
35 struct hlist_head m_list;
36 int m_count;
37};
38
39struct 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
84static inline struct mount *real_mount(struct vfsmount *mnt)
85{
86 return container_of(mnt, struct mount, mnt);
87}
88
89static inline int mnt_has_parent(struct mount *mnt)
90{
91 return mnt != mnt->mnt_parent;
92}
93
94static inline int is_mounted(struct vfsmount *mnt)
95{
96 /* neither detached nor internal? */
97 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
98}
99
100extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
101
102extern int __legitimize_mnt(struct vfsmount *, unsigned);
103extern bool legitimize_mnt(struct vfsmount *, unsigned);
104
105static inline bool __path_is_mountpoint(const struct path *path)
106{
107 struct mount *m = __lookup_mnt(path->mnt, path->dentry);
108 return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
109}
110
111extern void __detach_mounts(struct dentry *dentry);
112
113static inline void detach_mounts(struct dentry *dentry)
114{
115 if (!d_mountpoint(dentry))
116 return;
117 __detach_mounts(dentry);
118}
119
120static inline void get_mnt_ns(struct mnt_namespace *ns)
121{
122 refcount_inc(&ns->ns.count);
123}
124
125extern seqlock_t mount_lock;
126
127struct proc_mounts {
128 struct mnt_namespace *ns;
129 struct path root;
130 int (*show)(struct seq_file *, struct vfsmount *);
131 struct mount cursor;
132};
133
134extern const struct seq_operations mounts_op;
135
136extern bool __is_local_mountpoint(struct dentry *dentry);
137static inline bool is_local_mountpoint(struct dentry *dentry)
138{
139 if (!d_mountpoint(dentry))
140 return false;
141
142 return __is_local_mountpoint(dentry);
143}
144
145static inline bool is_anon_ns(struct mnt_namespace *ns)
146{
147 return ns->seq == 0;
148}
149
150extern void mnt_cursor_del(struct mnt_namespace *ns, struct mount *cursor);