tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 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
21struct mnt_pcp {
22 int mnt_count;
23 int mnt_writers;
24};
25
26struct mountpoint {
27 struct hlist_node m_hash;
28 struct dentry *m_dentry;
29 struct hlist_head m_list;
30 int m_count;
31};
32
33struct 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#ifdef CONFIG_FSNOTIFY
62 struct hlist_head mnt_fsnotify_marks;
63 __u32 mnt_fsnotify_mask;
64#endif
65 int mnt_id; /* mount identifier */
66 int mnt_group_id; /* peer group identifier */
67 int mnt_expiry_mark; /* true if marked for expiry */
68 struct hlist_head mnt_pins;
69 struct fs_pin mnt_umount;
70 struct dentry *mnt_ex_mountpoint;
71};
72
73#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
74
75static inline struct mount *real_mount(struct vfsmount *mnt)
76{
77 return container_of(mnt, struct mount, mnt);
78}
79
80static inline int mnt_has_parent(struct mount *mnt)
81{
82 return mnt != mnt->mnt_parent;
83}
84
85static inline int is_mounted(struct vfsmount *mnt)
86{
87 /* neither detached nor internal? */
88 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
89}
90
91extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
92extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
93
94extern int __legitimize_mnt(struct vfsmount *, unsigned);
95extern bool legitimize_mnt(struct vfsmount *, unsigned);
96
97extern void __detach_mounts(struct dentry *dentry);
98
99static inline void detach_mounts(struct dentry *dentry)
100{
101 if (!d_mountpoint(dentry))
102 return;
103 __detach_mounts(dentry);
104}
105
106static inline void get_mnt_ns(struct mnt_namespace *ns)
107{
108 atomic_inc(&ns->count);
109}
110
111extern seqlock_t mount_lock;
112
113static inline void lock_mount_hash(void)
114{
115 write_seqlock(&mount_lock);
116}
117
118static inline void unlock_mount_hash(void)
119{
120 write_sequnlock(&mount_lock);
121}
122
123struct 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
132extern const struct seq_operations mounts_op;
133
134extern bool __is_local_mountpoint(struct dentry *dentry);
135static 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}