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>
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.
17 struct list_head list
;
19 struct user_namespace
*user_ns
;
20 struct ucounts
*ucounts
;
21 u64 seq
; /* Sequence number to prevent loops */
22 wait_queue_head_t poll
;
24 unsigned int mounts
; /* # of mounts in the namespace */
25 unsigned int pending_mounts
;
34 struct hlist_node m_hash
;
35 struct dentry
*m_dentry
;
36 struct hlist_head m_list
;
41 struct hlist_node mnt_hash
;
42 struct mount
*mnt_parent
;
43 struct dentry
*mnt_mountpoint
;
46 struct rcu_head mnt_rcu
;
47 struct llist_node mnt_llist
;
50 struct mnt_pcp __percpu
*mnt_pcp
;
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 */
68 struct hlist_node mnt_mp_list
; /* list mounts with the same mountpoint */
69 struct hlist_node mnt_umount
;
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
;
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
;
83 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
85 static inline struct mount
*real_mount(struct vfsmount
*mnt
)
87 return container_of(mnt
, struct mount
, mnt
);
90 static inline int mnt_has_parent(struct mount
*mnt
)
92 return mnt
!= mnt
->mnt_parent
;
95 static inline int is_mounted(struct vfsmount
*mnt
)
97 /* neither detached nor internal? */
98 return !IS_ERR_OR_NULL(real_mount(mnt
)->mnt_ns
);
101 extern struct mount
*__lookup_mnt(struct vfsmount
*, struct dentry
*);
103 extern int __legitimize_mnt(struct vfsmount
*, unsigned);
104 extern bool legitimize_mnt(struct vfsmount
*, unsigned);
106 static inline bool __path_is_mountpoint(const struct path
*path
)
108 struct mount
*m
= __lookup_mnt(path
->mnt
, path
->dentry
);
109 return m
&& likely(!(m
->mnt
.mnt_flags
& MNT_SYNC_UMOUNT
));
112 extern void __detach_mounts(struct dentry
*dentry
);
114 static inline void detach_mounts(struct dentry
*dentry
)
116 if (!d_mountpoint(dentry
))
118 __detach_mounts(dentry
);
121 static inline void get_mnt_ns(struct mnt_namespace
*ns
)
123 atomic_inc(&ns
->count
);
126 extern seqlock_t mount_lock
;
128 static inline void lock_mount_hash(void)
130 write_seqlock(&mount_lock
);
133 static inline void unlock_mount_hash(void)
135 write_sequnlock(&mount_lock
);
139 struct mnt_namespace
*ns
;
141 int (*show
)(struct seq_file
*, struct vfsmount
*);
145 extern const struct seq_operations mounts_op
;
147 extern bool __is_local_mountpoint(struct dentry
*dentry
);
148 static inline bool is_local_mountpoint(struct dentry
*dentry
)
150 if (!d_mountpoint(dentry
))
153 return __is_local_mountpoint(dentry
);
156 static inline bool is_anon_ns(struct mnt_namespace
*ns
)
161 extern void mnt_cursor_del(struct mnt_namespace
*ns
, struct mount
*cursor
);