Loading...
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 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);
103
104static 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
110extern void __detach_mounts(struct dentry *dentry);
111
112static inline void detach_mounts(struct dentry *dentry)
113{
114 if (!d_mountpoint(dentry))
115 return;
116 __detach_mounts(dentry);
117}
118
119static inline void get_mnt_ns(struct mnt_namespace *ns)
120{
121 refcount_inc(&ns->ns.count);
122}
123
124extern seqlock_t mount_lock;
125
126struct 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
133extern const struct seq_operations mounts_op;
134
135extern bool __is_local_mountpoint(struct dentry *dentry);
136static 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
144static inline bool is_anon_ns(struct mnt_namespace *ns)
145{
146 return ns->seq == 0;
147}
148
149extern void mnt_cursor_del(struct mnt_namespace *ns, struct mount *cursor);