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 unsigned int mounts; /* # of mounts in the namespace */ 18 unsigned int pending_mounts; 19 }; 20 21 struct mnt_pcp { 22 int mnt_count; 23 int mnt_writers; 24 }; 25 26 struct mountpoint { 27 struct hlist_node m_hash; 28 struct dentry *m_dentry; 29 struct hlist_head m_list; 30 int m_count; 31 }; 32 33 struct mount { 34 struct hlist_node mnt_hash; 35 struct mount *mnt_parent; 36 struct dentry *mnt_mountpoint; 37 struct vfsmount mnt; 38 union { 39 struct rcu_head mnt_rcu; 40 struct llist_node mnt_llist; 41 }; 42 #ifdef CONFIG_SMP 43 struct mnt_pcp __percpu *mnt_pcp; 44 #else 45 int mnt_count; 46 int mnt_writers; 47 #endif 48 struct list_head mnt_mounts; /* list of children, anchored here */ 49 struct list_head mnt_child; /* and going through their mnt_child */ 50 struct list_head mnt_instance; /* mount instance on sb->s_mounts */ 51 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 52 struct list_head mnt_list; 53 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 */ 57 struct mount *mnt_master; /* slave is on master->mnt_slave_list */ 58 struct mnt_namespace *mnt_ns; /* containing namespace */ 59 struct mountpoint *mnt_mp; /* where is it mounted */ 60 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ 61 #ifdef CONFIG_FSNOTIFY 62 struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks; 63 __u32 mnt_fsnotify_mask; 64 #endif 65 int mnt_id; /* mount identifier */ 66 int mnt_group_id; /* peer group identifier */ 67 int mnt_expiry_mark; /* true if marked for expiry */ 68 struct hlist_head mnt_pins; 69 struct fs_pin mnt_umount; 70 struct dentry *mnt_ex_mountpoint; 71 }; 72 73 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ 74 75 static inline struct mount *real_mount(struct vfsmount *mnt) 76 { 77 return container_of(mnt, struct mount, mnt); 78 } 79 80 static inline int mnt_has_parent(struct mount *mnt) 81 { 82 return mnt != mnt->mnt_parent; 83 } 84 85 static inline int is_mounted(struct vfsmount *mnt) 86 { 87 /* neither detached nor internal? */ 88 return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns); 89 } 90 91 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *); 92 93 extern int __legitimize_mnt(struct vfsmount *, unsigned); 94 extern bool legitimize_mnt(struct vfsmount *, unsigned); 95 96 static inline bool __path_is_mountpoint(const struct path *path) 97 { 98 struct mount *m = __lookup_mnt(path->mnt, path->dentry); 99 return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT)); 100 } 101 102 extern void __detach_mounts(struct dentry *dentry); 103 104 static inline void detach_mounts(struct dentry *dentry) 105 { 106 if (!d_mountpoint(dentry)) 107 return; 108 __detach_mounts(dentry); 109 } 110 111 static inline void get_mnt_ns(struct mnt_namespace *ns) 112 { 113 atomic_inc(&ns->count); 114 } 115 116 extern seqlock_t mount_lock; 117 118 static inline void lock_mount_hash(void) 119 { 120 write_seqlock(&mount_lock); 121 } 122 123 static inline void unlock_mount_hash(void) 124 { 125 write_sequnlock(&mount_lock); 126 } 127 128 struct proc_mounts { 129 struct mnt_namespace *ns; 130 struct path root; 131 int (*show)(struct seq_file *, struct vfsmount *); 132 void *cached_mount; 133 u64 cached_event; 134 loff_t cached_index; 135 }; 136 137 extern const struct seq_operations mounts_op; 138 139 extern bool __is_local_mountpoint(struct dentry *dentry); 140 static inline bool is_local_mountpoint(struct dentry *dentry) 141 { 142 if (!d_mountpoint(dentry)) 143 return false; 144 145 return __is_local_mountpoint(dentry); 146 } 147