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 unsigned int mounts; /* # of mounts in the namespace */ 17 unsigned int pending_mounts; 18 }; 19 20 struct mnt_pcp { 21 int mnt_count; 22 int mnt_writers; 23 }; 24 25 struct mountpoint { 26 struct hlist_node m_hash; 27 struct dentry *m_dentry; 28 struct hlist_head m_list; 29 int m_count; 30 }; 31 32 struct mount { 33 struct hlist_node mnt_hash; 34 struct mount *mnt_parent; 35 struct dentry *mnt_mountpoint; 36 struct vfsmount mnt; 37 union { 38 struct rcu_head mnt_rcu; 39 struct llist_node mnt_llist; 40 }; 41 #ifdef CONFIG_SMP 42 struct mnt_pcp __percpu *mnt_pcp; 43 #else 44 int mnt_count; 45 int mnt_writers; 46 #endif 47 struct list_head mnt_mounts; /* list of children, anchored here */ 48 struct list_head mnt_child; /* and going through their mnt_child */ 49 struct list_head mnt_instance; /* mount instance on sb->s_mounts */ 50 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 51 struct list_head mnt_list; 52 struct list_head mnt_expire; /* link in fs-specific expiry list */ 53 struct list_head mnt_share; /* circular list of shared mounts */ 54 struct list_head mnt_slave_list;/* list of slave mounts */ 55 struct list_head mnt_slave; /* slave list entry */ 56 struct mount *mnt_master; /* slave is on master->mnt_slave_list */ 57 struct mnt_namespace *mnt_ns; /* containing namespace */ 58 struct mountpoint *mnt_mp; /* where is it mounted */ 59 struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ 60 struct list_head mnt_umounting; /* list entry for umount propagation */ 61 #ifdef CONFIG_FSNOTIFY 62 struct hlist_head 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 real_mount(struct vfsmount * mnt)75static inline struct mount *real_mount(struct vfsmount *mnt) 76 { 77 return container_of(mnt, struct mount, mnt); 78 } 79 mnt_has_parent(struct mount * mnt)80static inline int mnt_has_parent(struct mount *mnt) 81 { 82 return mnt != mnt->mnt_parent; 83 } 84 is_mounted(struct vfsmount * mnt)85static 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 extern void __detach_mounts(struct dentry *dentry); 97 detach_mounts(struct dentry * dentry)98static inline void detach_mounts(struct dentry *dentry) 99 { 100 if (!d_mountpoint(dentry)) 101 return; 102 __detach_mounts(dentry); 103 } 104 get_mnt_ns(struct mnt_namespace * ns)105static inline void get_mnt_ns(struct mnt_namespace *ns) 106 { 107 atomic_inc(&ns->count); 108 } 109 110 extern seqlock_t mount_lock; 111 lock_mount_hash(void)112static inline void lock_mount_hash(void) 113 { 114 write_seqlock(&mount_lock); 115 } 116 unlock_mount_hash(void)117static inline void unlock_mount_hash(void) 118 { 119 write_sequnlock(&mount_lock); 120 } 121 122 struct proc_mounts { 123 struct mnt_namespace *ns; 124 struct path root; 125 int (*show)(struct seq_file *, struct vfsmount *); 126 void *cached_mount; 127 u64 cached_event; 128 loff_t cached_index; 129 }; 130 131 extern const struct seq_operations mounts_op; 132 133 extern bool __is_local_mountpoint(struct dentry *dentry); is_local_mountpoint(struct dentry * dentry)134static inline bool is_local_mountpoint(struct dentry *dentry) 135 { 136 if (!d_mountpoint(dentry)) 137 return false; 138 139 return __is_local_mountpoint(dentry); 140 } 141