xref: /linux/fs/mount.h (revision d0b464d67001d202e59f7e60a30074c4d74021aa)
1 #include <linux/mount.h>
2 #include <linux/seq_file.h>
3 #include <linux/poll.h>
4 
5 struct mnt_namespace {
6 	atomic_t		count;
7 	struct mount *	root;
8 	struct list_head	list;
9 	wait_queue_head_t poll;
10 	int event;
11 };
12 
13 struct mnt_pcp {
14 	int mnt_count;
15 	int mnt_writers;
16 };
17 
18 struct mount {
19 	struct list_head mnt_hash;
20 	struct mount *mnt_parent;
21 	struct dentry *mnt_mountpoint;
22 	struct vfsmount mnt;
23 #ifdef CONFIG_SMP
24 	struct mnt_pcp __percpu *mnt_pcp;
25 #else
26 	int mnt_count;
27 	int mnt_writers;
28 #endif
29 	struct list_head mnt_mounts;	/* list of children, anchored here */
30 	struct list_head mnt_child;	/* and going through their mnt_child */
31 	struct list_head mnt_instance;	/* mount instance on sb->s_mounts */
32 	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
33 	struct list_head mnt_list;
34 	struct list_head mnt_expire;	/* link in fs-specific expiry list */
35 	struct list_head mnt_share;	/* circular list of shared mounts */
36 	struct list_head mnt_slave_list;/* list of slave mounts */
37 	struct list_head mnt_slave;	/* slave list entry */
38 	struct mount *mnt_master;	/* slave is on master->mnt_slave_list */
39 	struct mnt_namespace *mnt_ns;	/* containing namespace */
40 #ifdef CONFIG_FSNOTIFY
41 	struct hlist_head mnt_fsnotify_marks;
42 	__u32 mnt_fsnotify_mask;
43 #endif
44 	int mnt_id;			/* mount identifier */
45 	int mnt_group_id;		/* peer group identifier */
46 	int mnt_expiry_mark;		/* true if marked for expiry */
47 	int mnt_pinned;
48 	int mnt_ghosts;
49 };
50 
51 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
52 
53 static inline struct mount *real_mount(struct vfsmount *mnt)
54 {
55 	return container_of(mnt, struct mount, mnt);
56 }
57 
58 static inline int mnt_has_parent(struct mount *mnt)
59 {
60 	return mnt != mnt->mnt_parent;
61 }
62 
63 static inline int is_mounted(struct vfsmount *mnt)
64 {
65 	/* neither detached nor internal? */
66 	return !IS_ERR_OR_NULL(real_mount(mnt));
67 }
68 
69 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
70 
71 static inline void get_mnt_ns(struct mnt_namespace *ns)
72 {
73 	atomic_inc(&ns->count);
74 }
75 
76 struct proc_mounts {
77 	struct seq_file m;
78 	struct mnt_namespace *ns;
79 	struct path root;
80 	int (*show)(struct seq_file *, struct vfsmount *);
81 };
82 
83 #define proc_mounts(p) (container_of((p), struct proc_mounts, m))
84 
85 extern const struct seq_operations mounts_op;
86