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
6struct mnt_namespace {
7 atomic_t count;
8 struct ns_common ns;
9 struct mount * root;
10 struct list_head list;
11 struct user_namespace *user_ns;
12 u64 seq; /* Sequence number to prevent loops */
13 wait_queue_head_t poll;
14 u64 event;
15};
16
17struct mnt_pcp {
18 int mnt_count;
19 int mnt_writers;
20};
21
22struct mountpoint {
23 struct hlist_node m_hash;
24 struct dentry *m_dentry;
25 struct hlist_head m_list;
26 int m_count;
27};
28
29struct mount {
30 struct hlist_node mnt_hash;
31 struct mount *mnt_parent;
32 struct dentry *mnt_mountpoint;
33 struct vfsmount mnt;
34 union {
35 struct rcu_head mnt_rcu;
36 struct llist_node mnt_llist;
37 };
38#ifdef CONFIG_SMP
39 struct mnt_pcp __percpu *mnt_pcp;
40#else
41 int mnt_count;
42 int mnt_writers;
43#endif
44 struct list_head mnt_mounts; /* list of children, anchored here */
45 struct list_head mnt_child; /* and going through their mnt_child */
46 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
47 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
48 struct list_head mnt_list;
49 struct list_head mnt_expire; /* link in fs-specific expiry list */
50 struct list_head mnt_share; /* circular list of shared mounts */
51 struct list_head mnt_slave_list;/* list of slave mounts */
52 struct list_head mnt_slave; /* slave list entry */
53 struct mount *mnt_master; /* slave is on master->mnt_slave_list */
54 struct mnt_namespace *mnt_ns; /* containing namespace */
55 struct mountpoint *mnt_mp; /* where is it mounted */
56 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
57#ifdef CONFIG_FSNOTIFY
58 struct hlist_head mnt_fsnotify_marks;
59 __u32 mnt_fsnotify_mask;
60#endif
61 int mnt_id; /* mount identifier */
62 int mnt_group_id; /* peer group identifier */
63 int mnt_expiry_mark; /* true if marked for expiry */
64 struct hlist_head mnt_pins;
65 struct path mnt_ex_mountpoint;
66};
67
68#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
69
70static inline struct mount *real_mount(struct vfsmount *mnt)
71{
72 return container_of(mnt, struct mount, mnt);
73}
74
75static inline int mnt_has_parent(struct mount *mnt)
76{
77 return mnt != mnt->mnt_parent;
78}
79
80static inline int is_mounted(struct vfsmount *mnt)
81{
82 /* neither detached nor internal? */
83 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
84}
85
86extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
87extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
88
89extern bool legitimize_mnt(struct vfsmount *, unsigned);
90
91extern void __detach_mounts(struct dentry *dentry);
92
93static inline void detach_mounts(struct dentry *dentry)
94{
95 if (!d_mountpoint(dentry))
96 return;
97 __detach_mounts(dentry);
98}
99
100static inline void get_mnt_ns(struct mnt_namespace *ns)
101{
102 atomic_inc(&ns->count);
103}
104
105extern seqlock_t mount_lock;
106
107static inline void lock_mount_hash(void)
108{
109 write_seqlock(&mount_lock);
110}
111
112static inline void unlock_mount_hash(void)
113{
114 write_sequnlock(&mount_lock);
115}
116
117struct proc_mounts {
118 struct seq_file m;
119 struct mnt_namespace *ns;
120 struct path root;
121 int (*show)(struct seq_file *, struct vfsmount *);
122 void *cached_mount;
123 u64 cached_event;
124 loff_t cached_index;
125};
126
127#define proc_mounts(p) (container_of((p), struct proc_mounts, m))
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}