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 unsigned int proc_inum; 8 struct mount * root; 9 struct list_head list; 10 struct user_namespace *user_ns; 11 u64 seq; /* Sequence number to prevent loops */ 12 wait_queue_head_t poll; 13 u64 event; 14 }; 15 16 struct mnt_pcp { 17 int mnt_count; 18 int mnt_writers; 19 }; 20 21 struct mountpoint { 22 struct hlist_node m_hash; 23 struct dentry *m_dentry; 24 struct hlist_head m_list; 25 int m_count; 26 }; 27 28 struct mount { 29 struct hlist_node mnt_hash; 30 struct mount *mnt_parent; 31 struct dentry *mnt_mountpoint; 32 struct vfsmount mnt; 33 union { 34 struct rcu_head mnt_rcu; 35 struct llist_node mnt_llist; 36 }; 37 #ifdef CONFIG_SMP 38 struct mnt_pcp __percpu *mnt_pcp; 39 #else 40 int mnt_count; 41 int mnt_writers; 42 #endif 43 struct list_head mnt_mounts; /* list of children, anchored here */ 44 struct list_head mnt_child; /* and going through their mnt_child */ 45 struct list_head mnt_instance; /* mount instance on sb->s_mounts */ 46 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 47 struct list_head mnt_list; 48 struct list_head mnt_expire; /* link in fs-specific expiry list */ 49 struct list_head mnt_share; /* circular list of shared mounts */ 50 struct list_head mnt_slave_list;/* list of slave mounts */ 51 struct list_head mnt_slave; /* slave list entry */ 52 struct mount *mnt_master; /* slave is on master->mnt_slave_list */ 53 struct mnt_namespace *mnt_ns; /* containing namespace */ 54 struct mountpoint *mnt_mp; /* where is it mounted */ 55 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ 56 #ifdef CONFIG_FSNOTIFY 57 struct hlist_head mnt_fsnotify_marks; 58 __u32 mnt_fsnotify_mask; 59 #endif 60 int mnt_id; /* mount identifier */ 61 int mnt_group_id; /* peer group identifier */ 62 int mnt_expiry_mark; /* true if marked for expiry */ 63 struct hlist_head mnt_pins; 64 struct path mnt_ex_mountpoint; 65 }; 66 67 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ 68 69 static inline struct mount *real_mount(struct vfsmount *mnt) 70 { 71 return container_of(mnt, struct mount, mnt); 72 } 73 74 static inline int mnt_has_parent(struct mount *mnt) 75 { 76 return mnt != mnt->mnt_parent; 77 } 78 79 static inline int is_mounted(struct vfsmount *mnt) 80 { 81 /* neither detached nor internal? */ 82 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns); 83 } 84 85 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); 86 extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *); 87 88 extern bool legitimize_mnt(struct vfsmount *, unsigned); 89 90 extern void __detach_mounts(struct dentry *dentry); 91 92 static inline void detach_mounts(struct dentry *dentry) 93 { 94 if (!d_mountpoint(dentry)) 95 return; 96 __detach_mounts(dentry); 97 } 98 99 static inline void get_mnt_ns(struct mnt_namespace *ns) 100 { 101 atomic_inc(&ns->count); 102 } 103 104 extern seqlock_t mount_lock; 105 106 static inline void lock_mount_hash(void) 107 { 108 write_seqlock(&mount_lock); 109 } 110 111 static inline void unlock_mount_hash(void) 112 { 113 write_sequnlock(&mount_lock); 114 } 115 116 struct proc_mounts { 117 struct seq_file m; 118 struct mnt_namespace *ns; 119 struct path root; 120 int (*show)(struct seq_file *, struct vfsmount *); 121 void *cached_mount; 122 u64 cached_event; 123 loff_t cached_index; 124 }; 125 126 #define proc_mounts(p) (container_of((p), struct proc_mounts, m)) 127 128 extern const struct seq_operations mounts_op; 129 130 extern bool __is_local_mountpoint(struct dentry *dentry); 131 static inline bool is_local_mountpoint(struct dentry *dentry) 132 { 133 if (!d_mountpoint(dentry)) 134 return false; 135 136 return __is_local_mountpoint(dentry); 137 } 138