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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. Biederman537f7cc2016-08-08 14:37:37 -050013 struct ucounts *ucounts;
Eric W. Biederman8823c072010-03-07 18:49:36 -080014 u64 seq; /* Sequence number to prevent loops */
Al Viro0226f492011-12-06 12:21:54 -050015 wait_queue_head_t poll;
Al Viroc7999c32014-02-27 14:40:10 -050016 u64 event;
Eric W. Biedermand2921682016-09-28 00:27:17 -050017 unsigned int mounts; /* # of mounts in the namespace */
18 unsigned int pending_mounts;
Kees Cook3859a272016-10-28 01:22:25 -070019} __randomize_layout;
Al Virob2dba1a2011-11-23 19:26:23 -050020
Al Viro68e8a9f2011-11-24 22:53:09 -050021struct mnt_pcp {
22 int mnt_count;
23 int mnt_writers;
24};
25
Al Viro84d17192013-03-15 10:53:28 -040026struct mountpoint {
Al Viro0818bf22014-02-28 13:46:44 -050027 struct hlist_node m_hash;
Al Viro84d17192013-03-15 10:53:28 -040028 struct dentry *m_dentry;
Eric W. Biederman0a5eb7c2013-09-22 19:37:01 -070029 struct hlist_head m_list;
Al Viro84d17192013-03-15 10:53:28 -040030 int m_count;
31};
32
Al Viro7d6fec42011-11-23 12:14:10 -050033struct mount {
Al Viro38129a12014-03-20 21:10:51 -040034 struct hlist_node mnt_hash;
Al Viro0714a532011-11-24 22:19:58 -050035 struct mount *mnt_parent;
Al Viroa73324d2011-11-24 22:25:07 -050036 struct dentry *mnt_mountpoint;
Al Viro7d6fec42011-11-23 12:14:10 -050037 struct vfsmount mnt;
Al Viro9ea459e2014-08-08 13:08:20 -040038 union {
39 struct rcu_head mnt_rcu;
40 struct llist_node mnt_llist;
41 };
Al Viro68e8a9f2011-11-24 22:53:09 -050042#ifdef CONFIG_SMP
43 struct mnt_pcp __percpu *mnt_pcp;
Al Viro68e8a9f2011-11-24 22:53:09 -050044#else
45 int mnt_count;
46 int mnt_writers;
47#endif
Al Viro6b41d532011-11-24 23:24:33 -050048 struct list_head mnt_mounts; /* list of children, anchored here */
49 struct list_head mnt_child; /* and going through their mnt_child */
Miklos Szeredi39f7c4d2011-11-21 12:11:30 +010050 struct list_head mnt_instance; /* mount instance on sb->s_mounts */
Al Viro52ba1622011-11-25 02:25:17 -050051 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
Al Viro1a4eeaf2011-11-25 02:19:55 -050052 struct list_head mnt_list;
Al Viro6776db3d2011-11-25 00:22:05 -050053 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 */
Al Viro32301922011-11-25 00:10:28 -050057 struct mount *mnt_master; /* slave is on master->mnt_slave_list */
Al Viro143c8c92011-11-25 00:46:35 -050058 struct mnt_namespace *mnt_ns; /* containing namespace */
Al Viro84d17192013-03-15 10:53:28 -040059 struct mountpoint *mnt_mp; /* where is it mounted */
Eric W. Biederman0a5eb7c2013-09-22 19:37:01 -070060 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
Eric W. Biederman99b19d12016-10-24 16:16:13 -050061 struct list_head mnt_umounting; /* list entry for umount propagation */
Al Viroc63181e2011-11-25 02:35:16 -050062#ifdef CONFIG_FSNOTIFY
Jan Kara08991e82017-02-01 09:21:58 +010063 struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
Al Viroc63181e2011-11-25 02:35:16 -050064 __u32 mnt_fsnotify_mask;
65#endif
Al Viro15169fe2011-11-25 00:50:41 -050066 int mnt_id; /* mount identifier */
67 int mnt_group_id; /* peer group identifier */
Al Viro863d6842011-11-25 00:57:42 -050068 int mnt_expiry_mark; /* true if marked for expiry */
Al Viro215752f2014-08-07 06:23:41 -040069 struct hlist_head mnt_pins;
Al Viro87b95ce2015-01-10 19:01:08 -050070 struct fs_pin mnt_umount;
71 struct dentry *mnt_ex_mountpoint;
Kees Cook3859a272016-10-28 01:22:25 -070072} __randomize_layout;
Al Viro7d6fec42011-11-23 12:14:10 -050073
Al Virof7a99c52012-06-09 00:59:08 -040074#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
75
Al Viro7d6fec42011-11-23 12:14:10 -050076static inline struct mount *real_mount(struct vfsmount *mnt)
77{
78 return container_of(mnt, struct mount, mnt);
79}
80
Al Viro676da582011-11-24 21:47:05 -050081static inline int mnt_has_parent(struct mount *mnt)
Al Virob2dba1a2011-11-23 19:26:23 -050082{
Al Viro0714a532011-11-24 22:19:58 -050083 return mnt != mnt->mnt_parent;
Al Virob2dba1a2011-11-23 19:26:23 -050084}
Al Viroc7105362011-11-24 18:22:03 -050085
Al Virof7a99c52012-06-09 00:59:08 -040086static inline int is_mounted(struct vfsmount *mnt)
87{
88 /* neither detached nor internal? */
Eric W. Biederman260a4592014-01-20 15:26:15 -080089 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
Al Virof7a99c52012-06-09 00:59:08 -040090}
91
Al Viro474279d2013-10-01 16:11:26 -040092extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
Al Viro0226f492011-12-06 12:21:54 -050093
Al Viro294d71f2015-05-08 11:43:53 -040094extern int __legitimize_mnt(struct vfsmount *, unsigned);
Al Viro48a066e2013-09-29 22:06:07 -040095extern bool legitimize_mnt(struct vfsmount *, unsigned);
96
Ian Kentc6609c02016-11-24 08:03:41 +110097static inline bool __path_is_mountpoint(const struct path *path)
98{
99 struct mount *m = __lookup_mnt(path->mnt, path->dentry);
100 return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
101}
102
Eric W. Biederman80b5dce2013-10-03 01:31:18 -0700103extern void __detach_mounts(struct dentry *dentry);
104
105static inline void detach_mounts(struct dentry *dentry)
106{
107 if (!d_mountpoint(dentry))
108 return;
109 __detach_mounts(dentry);
110}
111
Al Viro0226f492011-12-06 12:21:54 -0500112static inline void get_mnt_ns(struct mnt_namespace *ns)
113{
114 atomic_inc(&ns->count);
115}
116
Al Viro48a066e2013-09-29 22:06:07 -0400117extern seqlock_t mount_lock;
Al Viro719ea2f2013-09-29 11:24:49 -0400118
119static inline void lock_mount_hash(void)
120{
Al Viro48a066e2013-09-29 22:06:07 -0400121 write_seqlock(&mount_lock);
Al Viro719ea2f2013-09-29 11:24:49 -0400122}
123
124static inline void unlock_mount_hash(void)
125{
Al Viro48a066e2013-09-29 22:06:07 -0400126 write_sequnlock(&mount_lock);
Al Viro719ea2f2013-09-29 11:24:49 -0400127}
128
Al Viro0226f492011-12-06 12:21:54 -0500129struct proc_mounts {
Al Viro0226f492011-12-06 12:21:54 -0500130 struct mnt_namespace *ns;
131 struct path root;
132 int (*show)(struct seq_file *, struct vfsmount *);
Al Viroc7999c32014-02-27 14:40:10 -0500133 void *cached_mount;
134 u64 cached_event;
135 loff_t cached_index;
Al Viro0226f492011-12-06 12:21:54 -0500136};
137
138extern const struct seq_operations mounts_op;
Eric W. Biederman7af13642013-10-04 19:15:13 -0700139
140extern bool __is_local_mountpoint(struct dentry *dentry);
141static inline bool is_local_mountpoint(struct dentry *dentry)
142{
143 if (!d_mountpoint(dentry))
144 return false;
145
146 return __is_local_mountpoint(dentry);
147}