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1#include <linux/mount.h>
2#include <linux/seq_file.h>
3#include <linux/poll.h>
4#include <linux/ns_common.h>
5#include <linux/fs_pin.h>
6
7struct mnt_namespace {
8 atomic_t count;
9 struct ns_common ns;
10 struct mount * root;
11 struct list_head list;
12 struct user_namespace *user_ns;
13 u64 seq; /* Sequence number to prevent loops */
14 wait_queue_head_t poll;
15 u64 event;
16};
17
18struct mnt_pcp {
19 int mnt_count;
20 int mnt_writers;
21};
22
23struct mountpoint {
24 struct hlist_node m_hash;
25 struct dentry *m_dentry;
26 struct hlist_head m_list;
27 int m_count;
28};
29
30struct mount {
31 struct hlist_node mnt_hash;
32 struct mount *mnt_parent;
33 struct dentry *mnt_mountpoint;
34 struct vfsmount mnt;
35 union {
36 struct rcu_head mnt_rcu;
37 struct llist_node mnt_llist;
38 };
39#ifdef CONFIG_SMP
40 struct mnt_pcp __percpu *mnt_pcp;
41#else
42 int mnt_count;
43 int mnt_writers;
44#endif
45 struct list_head mnt_mounts; /* list of children, anchored here */
46 struct list_head mnt_child; /* and going through their mnt_child */
47 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
48 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
49 struct list_head mnt_list;
50 struct list_head mnt_expire; /* link in fs-specific expiry list */
51 struct list_head mnt_share; /* circular list of shared mounts */
52 struct list_head mnt_slave_list;/* list of slave mounts */
53 struct list_head mnt_slave; /* slave list entry */
54 struct mount *mnt_master; /* slave is on master->mnt_slave_list */
55 struct mnt_namespace *mnt_ns; /* containing namespace */
56 struct mountpoint *mnt_mp; /* where is it mounted */
57 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
58#ifdef CONFIG_FSNOTIFY
59 struct hlist_head mnt_fsnotify_marks;
60 __u32 mnt_fsnotify_mask;
61#endif
62 int mnt_id; /* mount identifier */
63 int mnt_group_id; /* peer group identifier */
64 int mnt_expiry_mark; /* true if marked for expiry */
65 struct hlist_head mnt_pins;
66 struct fs_pin mnt_umount;
67 struct dentry *mnt_ex_mountpoint;
68};
69
70#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
71
72static inline struct mount *real_mount(struct vfsmount *mnt)
73{
74 return container_of(mnt, struct mount, mnt);
75}
76
77static inline int mnt_has_parent(struct mount *mnt)
78{
79 return mnt != mnt->mnt_parent;
80}
81
82static inline int is_mounted(struct vfsmount *mnt)
83{
84 /* neither detached nor internal? */
85 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
86}
87
88extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
89extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
90
91extern int __legitimize_mnt(struct vfsmount *, unsigned);
92extern bool legitimize_mnt(struct vfsmount *, unsigned);
93
94extern void __detach_mounts(struct dentry *dentry);
95
96static inline void detach_mounts(struct dentry *dentry)
97{
98 if (!d_mountpoint(dentry))
99 return;
100 __detach_mounts(dentry);
101}
102
103static inline void get_mnt_ns(struct mnt_namespace *ns)
104{
105 atomic_inc(&ns->count);
106}
107
108extern seqlock_t mount_lock;
109
110static inline void lock_mount_hash(void)
111{
112 write_seqlock(&mount_lock);
113}
114
115static inline void unlock_mount_hash(void)
116{
117 write_sequnlock(&mount_lock);
118}
119
120struct proc_mounts {
121 struct mnt_namespace *ns;
122 struct path root;
123 int (*show)(struct seq_file *, struct vfsmount *);
124 void *cached_mount;
125 u64 cached_event;
126 loff_t cached_index;
127};
128
129extern const struct seq_operations mounts_op;
130
131extern bool __is_local_mountpoint(struct dentry *dentry);
132static inline bool is_local_mountpoint(struct dentry *dentry)
133{
134 if (!d_mountpoint(dentry))
135 return false;
136
137 return __is_local_mountpoint(dentry);
138}
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 /*
13 * Traversal and modification of .list is protected by either
14 * - taking namespace_sem for write, OR
15 * - taking namespace_sem for read AND taking .ns_lock.
16 */
17 struct list_head list;
18 spinlock_t ns_lock;
19 struct user_namespace *user_ns;
20 struct ucounts *ucounts;
21 u64 seq; /* Sequence number to prevent loops */
22 wait_queue_head_t poll;
23 u64 event;
24 unsigned int mounts; /* # of mounts in the namespace */
25 unsigned int pending_mounts;
26} __randomize_layout;
27
28struct mnt_pcp {
29 int mnt_count;
30 int mnt_writers;
31};
32
33struct mountpoint {
34 struct hlist_node m_hash;
35 struct dentry *m_dentry;
36 struct hlist_head m_list;
37 int m_count;
38};
39
40struct mount {
41 struct hlist_node mnt_hash;
42 struct mount *mnt_parent;
43 struct dentry *mnt_mountpoint;
44 struct vfsmount mnt;
45 union {
46 struct rcu_head mnt_rcu;
47 struct llist_node mnt_llist;
48 };
49#ifdef CONFIG_SMP
50 struct mnt_pcp __percpu *mnt_pcp;
51#else
52 int mnt_count;
53 int mnt_writers;
54#endif
55 struct list_head mnt_mounts; /* list of children, anchored here */
56 struct list_head mnt_child; /* and going through their mnt_child */
57 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
58 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
59 struct list_head mnt_list;
60 struct list_head mnt_expire; /* link in fs-specific expiry list */
61 struct list_head mnt_share; /* circular list of shared mounts */
62 struct list_head mnt_slave_list;/* list of slave mounts */
63 struct list_head mnt_slave; /* slave list entry */
64 struct mount *mnt_master; /* slave is on master->mnt_slave_list */
65 struct mnt_namespace *mnt_ns; /* containing namespace */
66 struct mountpoint *mnt_mp; /* where is it mounted */
67 union {
68 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
69 struct hlist_node mnt_umount;
70 };
71 struct list_head mnt_umounting; /* list entry for umount propagation */
72#ifdef CONFIG_FSNOTIFY
73 struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
74 __u32 mnt_fsnotify_mask;
75#endif
76 int mnt_id; /* mount identifier */
77 int mnt_group_id; /* peer group identifier */
78 int mnt_expiry_mark; /* true if marked for expiry */
79 struct hlist_head mnt_pins;
80 struct hlist_head mnt_stuck_children;
81} __randomize_layout;
82
83#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
84
85static inline struct mount *real_mount(struct vfsmount *mnt)
86{
87 return container_of(mnt, struct mount, mnt);
88}
89
90static inline int mnt_has_parent(struct mount *mnt)
91{
92 return mnt != mnt->mnt_parent;
93}
94
95static inline int is_mounted(struct vfsmount *mnt)
96{
97 /* neither detached nor internal? */
98 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
99}
100
101extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
102
103extern int __legitimize_mnt(struct vfsmount *, unsigned);
104extern bool legitimize_mnt(struct vfsmount *, unsigned);
105
106static inline bool __path_is_mountpoint(const struct path *path)
107{
108 struct mount *m = __lookup_mnt(path->mnt, path->dentry);
109 return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
110}
111
112extern void __detach_mounts(struct dentry *dentry);
113
114static inline void detach_mounts(struct dentry *dentry)
115{
116 if (!d_mountpoint(dentry))
117 return;
118 __detach_mounts(dentry);
119}
120
121static inline void get_mnt_ns(struct mnt_namespace *ns)
122{
123 atomic_inc(&ns->count);
124}
125
126extern seqlock_t mount_lock;
127
128static inline void lock_mount_hash(void)
129{
130 write_seqlock(&mount_lock);
131}
132
133static inline void unlock_mount_hash(void)
134{
135 write_sequnlock(&mount_lock);
136}
137
138struct proc_mounts {
139 struct mnt_namespace *ns;
140 struct path root;
141 int (*show)(struct seq_file *, struct vfsmount *);
142 struct mount cursor;
143};
144
145extern const struct seq_operations mounts_op;
146
147extern bool __is_local_mountpoint(struct dentry *dentry);
148static inline bool is_local_mountpoint(struct dentry *dentry)
149{
150 if (!d_mountpoint(dentry))
151 return false;
152
153 return __is_local_mountpoint(dentry);
154}
155
156static inline bool is_anon_ns(struct mnt_namespace *ns)
157{
158 return ns->seq == 0;
159}
160
161extern void mnt_cursor_del(struct mnt_namespace *ns, struct mount *cursor);