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 u64 seq; /* Sequence number to prevent loops */ 14 wait_queue_head_t poll; 15 u64 event; 16 }; 17 18 struct mnt_pcp { 19 int mnt_count; 20 int mnt_writers; 21 }; 22 23 struct mountpoint { 24 struct hlist_node m_hash; 25 struct dentry *m_dentry; 26 struct hlist_head m_list; 27 int m_count; 28 }; 29 30 struct mount { 31 struct hlist_node mnt_hash; 32 struct mount *mnt_parent; 33 struct dentry *mnt_mountpoint; 34 struct vfsmount mnt; 35 union { 36 struct rcu_head mnt_rcu; 37 struct llist_node mnt_llist; 38 }; 39 #ifdef CONFIG_SMP 40 struct mnt_pcp __percpu *mnt_pcp; 41 #else 42 int mnt_count; 43 int mnt_writers; 44 #endif 45 struct list_head mnt_mounts; /* list of children, anchored here */ 46 struct list_head mnt_child; /* and going through their mnt_child */ 47 struct list_head mnt_instance; /* mount instance on sb->s_mounts */ 48 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 49 struct list_head mnt_list; 50 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 */ 54 struct mount *mnt_master; /* slave is on master->mnt_slave_list */ 55 struct mnt_namespace *mnt_ns; /* containing namespace */ 56 struct mountpoint *mnt_mp; /* where is it mounted */ 57 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ 58 #ifdef CONFIG_FSNOTIFY 59 struct hlist_head mnt_fsnotify_marks; 60 __u32 mnt_fsnotify_mask; 61 #endif 62 int mnt_id; /* mount identifier */ 63 int mnt_group_id; /* peer group identifier */ 64 int mnt_expiry_mark; /* true if marked for expiry */ 65 struct hlist_head mnt_pins; 66 struct fs_pin mnt_umount; 67 struct dentry *mnt_ex_mountpoint; 68 }; 69 70 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ 71 72 static inline struct mount *real_mount(struct vfsmount *mnt) 73 { 74 return container_of(mnt, struct mount, mnt); 75 } 76 77 static inline int mnt_has_parent(struct mount *mnt) 78 { 79 return mnt != mnt->mnt_parent; 80 } 81 82 static inline int is_mounted(struct vfsmount *mnt) 83 { 84 /* neither detached nor internal? */ 85 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns); 86 } 87 88 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); 89 extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *); 90 91 extern int __legitimize_mnt(struct vfsmount *, unsigned); 92 extern bool legitimize_mnt(struct vfsmount *, unsigned); 93 94 extern void __detach_mounts(struct dentry *dentry); 95 96 static inline void detach_mounts(struct dentry *dentry) 97 { 98 if (!d_mountpoint(dentry)) 99 return; 100 __detach_mounts(dentry); 101 } 102 103 static inline void get_mnt_ns(struct mnt_namespace *ns) 104 { 105 atomic_inc(&ns->count); 106 } 107 108 extern seqlock_t mount_lock; 109 110 static inline void lock_mount_hash(void) 111 { 112 write_seqlock(&mount_lock); 113 } 114 115 static inline void unlock_mount_hash(void) 116 { 117 write_sequnlock(&mount_lock); 118 } 119 120 struct proc_mounts { 121 struct seq_file m; 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 #define proc_mounts(p) (container_of((p), struct proc_mounts, m)) 131 132 extern const struct seq_operations mounts_op; 133 134 extern bool __is_local_mountpoint(struct dentry *dentry); 135 static inline bool is_local_mountpoint(struct dentry *dentry) 136 { 137 if (!d_mountpoint(dentry)) 138 return false; 139 140 return __is_local_mountpoint(dentry); 141 } 142