1 #include <linux/mount.h> 2 #include <linux/seq_file.h> 3 #include <linux/poll.h> 4 #include <linux/ns_common.h> 5 6 struct 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 17 struct mnt_pcp { 18 int mnt_count; 19 int mnt_writers; 20 }; 21 22 struct mountpoint { 23 struct hlist_node m_hash; 24 struct dentry *m_dentry; 25 struct hlist_head m_list; 26 int m_count; 27 }; 28 29 struct 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 70 static inline struct mount *real_mount(struct vfsmount *mnt) 71 { 72 return container_of(mnt, struct mount, mnt); 73 } 74 75 static inline int mnt_has_parent(struct mount *mnt) 76 { 77 return mnt != mnt->mnt_parent; 78 } 79 80 static 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 86 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); 87 extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *); 88 89 extern bool legitimize_mnt(struct vfsmount *, unsigned); 90 91 extern void __detach_mounts(struct dentry *dentry); 92 93 static inline void detach_mounts(struct dentry *dentry) 94 { 95 if (!d_mountpoint(dentry)) 96 return; 97 __detach_mounts(dentry); 98 } 99 100 static inline void get_mnt_ns(struct mnt_namespace *ns) 101 { 102 atomic_inc(&ns->count); 103 } 104 105 extern seqlock_t mount_lock; 106 107 static inline void lock_mount_hash(void) 108 { 109 write_seqlock(&mount_lock); 110 } 111 112 static inline void unlock_mount_hash(void) 113 { 114 write_sequnlock(&mount_lock); 115 } 116 117 struct 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)) 128 129 extern const struct seq_operations mounts_op; 130 131 extern bool __is_local_mountpoint(struct dentry *dentry); 132 static 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 } 139