blob: 14db05d424f7059d9bd035f88f9c50b719447ee8 [file] [log] [blame]
Al Virob2dba1a2011-11-23 19:26:23 -05001#include <linux/mount.h>
Al Viro0226f492011-12-06 12:21:54 -05002#include <linux/seq_file.h>
3#include <linux/poll.h>
Al Viro435d5f42014-10-31 22:56:04 -04004#include <linux/ns_common.h>
Al Viro87b95ce2015-01-10 19:01:08 -05005#include <linux/fs_pin.h>
Al Viro0226f492011-12-06 12:21:54 -05006
7struct mnt_namespace {
8 atomic_t count;
Al Viro435d5f42014-10-31 22:56:04 -04009 struct ns_common ns;
Al Virobe08d6d2011-12-06 13:32:36 -050010 struct mount * root;
Al Viro0226f492011-12-06 12:21:54 -050011 struct list_head list;
Eric W. Biederman771b1372012-07-26 21:08:32 -070012 struct user_namespace *user_ns;
Eric W. Biederman8823c072010-03-07 18:49:36 -080013 u64 seq; /* Sequence number to prevent loops */
Al Viro0226f492011-12-06 12:21:54 -050014 wait_queue_head_t poll;
Al Viroc7999c32014-02-27 14:40:10 -050015 u64 event;
Al Viro0226f492011-12-06 12:21:54 -050016};
Al Virob2dba1a2011-11-23 19:26:23 -050017
Al Viro68e8a9f2011-11-24 22:53:09 -050018struct mnt_pcp {
19 int mnt_count;
20 int mnt_writers;
21};
22
Al Viro84d17192013-03-15 10:53:28 -040023struct mountpoint {
Al Viro0818bf22014-02-28 13:46:44 -050024 struct hlist_node m_hash;
Al Viro84d17192013-03-15 10:53:28 -040025 struct dentry *m_dentry;
Eric W. Biederman0a5eb7c2013-09-22 19:37:01 -070026 struct hlist_head m_list;
Al Viro84d17192013-03-15 10:53:28 -040027 int m_count;
28};
29
Al Viro7d6fec42011-11-23 12:14:10 -050030struct mount {
Al Viro38129a12014-03-20 21:10:51 -040031 struct hlist_node mnt_hash;
Al Viro0714a532011-11-24 22:19:58 -050032 struct mount *mnt_parent;
Al Viroa73324d2011-11-24 22:25:07 -050033 struct dentry *mnt_mountpoint;
Al Viro7d6fec42011-11-23 12:14:10 -050034 struct vfsmount mnt;
Al Viro9ea459e2014-08-08 13:08:20 -040035 union {
36 struct rcu_head mnt_rcu;
37 struct llist_node mnt_llist;
38 };
Al Viro68e8a9f2011-11-24 22:53:09 -050039#ifdef CONFIG_SMP
40 struct mnt_pcp __percpu *mnt_pcp;
Al Viro68e8a9f2011-11-24 22:53:09 -050041#else
42 int mnt_count;
43 int mnt_writers;
44#endif
Al Viro6b41d532011-11-24 23:24:33 -050045 struct list_head mnt_mounts; /* list of children, anchored here */
46 struct list_head mnt_child; /* and going through their mnt_child */
Miklos Szeredi39f7c4d2011-11-21 12:11:30 +010047 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
Al Viro52ba1622011-11-25 02:25:17 -050048 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
Al Viro1a4eeaf2011-11-25 02:19:55 -050049 struct list_head mnt_list;
Al Viro6776db3d2011-11-25 00:22:05 -050050 struct list_head mnt_expire; /* link in fs-specific expiry list */
51 struct list_head mnt_share; /* circular list of shared mounts */
52 struct list_head mnt_slave_list;/* list of slave mounts */
53 struct list_head mnt_slave; /* slave list entry */
Al Viro32301922011-11-25 00:10:28 -050054 struct mount *mnt_master; /* slave is on master->mnt_slave_list */
Al Viro143c8c92011-11-25 00:46:35 -050055 struct mnt_namespace *mnt_ns; /* containing namespace */
Al Viro84d17192013-03-15 10:53:28 -040056 struct mountpoint *mnt_mp; /* where is it mounted */
Eric W. Biederman0a5eb7c2013-09-22 19:37:01 -070057 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
Al Viroc63181e2011-11-25 02:35:16 -050058#ifdef CONFIG_FSNOTIFY
59 struct hlist_head mnt_fsnotify_marks;
60 __u32 mnt_fsnotify_mask;
61#endif
Al Viro15169fe2011-11-25 00:50:41 -050062 int mnt_id; /* mount identifier */
63 int mnt_group_id; /* peer group identifier */
Al Viro863d6842011-11-25 00:57:42 -050064 int mnt_expiry_mark; /* true if marked for expiry */
Al Viro215752f2014-08-07 06:23:41 -040065 struct hlist_head mnt_pins;
Al Viro87b95ce2015-01-10 19:01:08 -050066 struct fs_pin mnt_umount;
67 struct dentry *mnt_ex_mountpoint;
Al Viro7d6fec42011-11-23 12:14:10 -050068};
69
Al Virof7a99c52012-06-09 00:59:08 -040070#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
71
Al Viro7d6fec42011-11-23 12:14:10 -050072static inline struct mount *real_mount(struct vfsmount *mnt)
73{
74 return container_of(mnt, struct mount, mnt);
75}
76
Al Viro676da582011-11-24 21:47:05 -050077static inline int mnt_has_parent(struct mount *mnt)
Al Virob2dba1a2011-11-23 19:26:23 -050078{
Al Viro0714a532011-11-24 22:19:58 -050079 return mnt != mnt->mnt_parent;
Al Virob2dba1a2011-11-23 19:26:23 -050080}
Al Viroc7105362011-11-24 18:22:03 -050081
Al Virof7a99c52012-06-09 00:59:08 -040082static inline int is_mounted(struct vfsmount *mnt)
83{
84 /* neither detached nor internal? */
Eric W. Biederman260a4592014-01-20 15:26:15 -080085 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
Al Virof7a99c52012-06-09 00:59:08 -040086}
87
Al Viro474279d2013-10-01 16:11:26 -040088extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
89extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
Al Viro0226f492011-12-06 12:21:54 -050090
Al Viro294d71f2015-05-08 11:43:53 -040091extern int __legitimize_mnt(struct vfsmount *, unsigned);
Al Viro48a066e2013-09-29 22:06:07 -040092extern bool legitimize_mnt(struct vfsmount *, unsigned);
93
Eric W. Biederman80b5dce2013-10-03 01:31:18 -070094extern void __detach_mounts(struct dentry *dentry);
95
96static inline void detach_mounts(struct dentry *dentry)
97{
98 if (!d_mountpoint(dentry))
99 return;
100 __detach_mounts(dentry);
101}
102
Al Viro0226f492011-12-06 12:21:54 -0500103static inline void get_mnt_ns(struct mnt_namespace *ns)
104{
105 atomic_inc(&ns->count);
106}
107
Al Viro48a066e2013-09-29 22:06:07 -0400108extern seqlock_t mount_lock;
Al Viro719ea2f2013-09-29 11:24:49 -0400109
110static inline void lock_mount_hash(void)
111{
Al Viro48a066e2013-09-29 22:06:07 -0400112 write_seqlock(&mount_lock);
Al Viro719ea2f2013-09-29 11:24:49 -0400113}
114
115static inline void unlock_mount_hash(void)
116{
Al Viro48a066e2013-09-29 22:06:07 -0400117 write_sequnlock(&mount_lock);
Al Viro719ea2f2013-09-29 11:24:49 -0400118}
119
Al Viro0226f492011-12-06 12:21:54 -0500120struct proc_mounts {
Al Viro0226f492011-12-06 12:21:54 -0500121 struct mnt_namespace *ns;
122 struct path root;
123 int (*show)(struct seq_file *, struct vfsmount *);
Al Viroc7999c32014-02-27 14:40:10 -0500124 void *cached_mount;
125 u64 cached_event;
126 loff_t cached_index;
Al Viro0226f492011-12-06 12:21:54 -0500127};
128
129extern const struct seq_operations mounts_op;
Eric W. Biederman7af13642013-10-04 19:15:13 -0700130
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}