1 #include <linux/mount.h> 2 #include <linux/seq_file.h> 3 #include <linux/poll.h> 4 #include <linux/ns_common.h> 5 #include <linux/fs_pin.h> 6 7 struct mnt_namespace { 8 atomic_t count; 9 struct ns_common ns; 10 struct mount * root; 11 struct list_head list; 12 struct user_namespace *user_ns; 13 struct ucounts *ucounts; 14 u64 seq; /* Sequence number to prevent loops */ 15 wait_queue_head_t poll; 16 u64 event; 17 }; 18 19 struct mnt_pcp { 20 int mnt_count; 21 int mnt_writers; 22 }; 23 24 struct mountpoint { 25 struct hlist_node m_hash; 26 struct dentry *m_dentry; 27 struct hlist_head m_list; 28 int m_count; 29 }; 30 31 struct mount { 32 struct hlist_node mnt_hash; 33 struct mount *mnt_parent; 34 struct dentry *mnt_mountpoint; 35 struct vfsmount mnt; 36 union { 37 struct rcu_head mnt_rcu; 38 struct llist_node mnt_llist; 39 }; 40 #ifdef CONFIG_SMP 41 struct mnt_pcp __percpu *mnt_pcp; 42 #else 43 int mnt_count; 44 int mnt_writers; 45 #endif 46 struct list_head mnt_mounts; /* list of children, anchored here */ 47 struct list_head mnt_child; /* and going through their mnt_child */ 48 struct list_head mnt_instance; /* mount instance on sb->s_mounts */ 49 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 50 struct list_head mnt_list; 51 struct list_head mnt_expire; /* link in fs-specific expiry list */ 52 struct list_head mnt_share; /* circular list of shared mounts */ 53 struct list_head mnt_slave_list;/* list of slave mounts */ 54 struct list_head mnt_slave; /* slave list entry */ 55 struct mount *mnt_master; /* slave is on master->mnt_slave_list */ 56 struct mnt_namespace *mnt_ns; /* containing namespace */ 57 struct mountpoint *mnt_mp; /* where is it mounted */ 58 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ 59 #ifdef CONFIG_FSNOTIFY 60 struct hlist_head mnt_fsnotify_marks; 61 __u32 mnt_fsnotify_mask; 62 #endif 63 int mnt_id; /* mount identifier */ 64 int mnt_group_id; /* peer group identifier */ 65 int mnt_expiry_mark; /* true if marked for expiry */ 66 struct hlist_head mnt_pins; 67 struct fs_pin mnt_umount; 68 struct dentry *mnt_ex_mountpoint; 69 }; 70 71 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ 72 73 static inline struct mount *real_mount(struct vfsmount *mnt) 74 { 75 return container_of(mnt, struct mount, mnt); 76 } 77 78 static inline int mnt_has_parent(struct mount *mnt) 79 { 80 return mnt != mnt->mnt_parent; 81 } 82 83 static inline int is_mounted(struct vfsmount *mnt) 84 { 85 /* neither detached nor internal? */ 86 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns); 87 } 88 89 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); 90 extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *); 91 92 extern int __legitimize_mnt(struct vfsmount *, unsigned); 93 extern bool legitimize_mnt(struct vfsmount *, unsigned); 94 95 extern void __detach_mounts(struct dentry *dentry); 96 97 static inline void detach_mounts(struct dentry *dentry) 98 { 99 if (!d_mountpoint(dentry)) 100 return; 101 __detach_mounts(dentry); 102 } 103 104 static inline void get_mnt_ns(struct mnt_namespace *ns) 105 { 106 atomic_inc(&ns->count); 107 } 108 109 extern seqlock_t mount_lock; 110 111 static inline void lock_mount_hash(void) 112 { 113 write_seqlock(&mount_lock); 114 } 115 116 static inline void unlock_mount_hash(void) 117 { 118 write_sequnlock(&mount_lock); 119 } 120 121 struct proc_mounts { 122 struct mnt_namespace *ns; 123 struct path root; 124 int (*show)(struct seq_file *, struct vfsmount *); 125 void *cached_mount; 126 u64 cached_event; 127 loff_t cached_index; 128 }; 129 130 extern const struct seq_operations mounts_op; 131 132 extern bool __is_local_mountpoint(struct dentry *dentry); 133 static inline bool is_local_mountpoint(struct dentry *dentry) 134 { 135 if (!d_mountpoint(dentry)) 136 return false; 137 138 return __is_local_mountpoint(dentry); 139 } 140