path: root/fs/mount.h (plain)
blob: 3603884a63ddb1bf84a62c5a28c14be2c762d2ff

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