diff options
Diffstat (limited to 'fs/mount.h')
| -rw-r--r-- | fs/mount.h | 112 |
1 files changed, 88 insertions, 24 deletions
diff --git a/fs/mount.h b/fs/mount.h index 185fc56afc13..97737051a8b9 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -5,18 +5,33 @@ #include <linux/ns_common.h> #include <linux/fs_pin.h> +extern struct list_head notify_list; + struct mnt_namespace { struct ns_common ns; struct mount * root; - struct rb_root mounts; /* Protected by namespace_sem */ + struct { + struct rb_root mounts; /* Protected by namespace_sem */ + struct rb_node *mnt_last_node; /* last (rightmost) mount in the rbtree */ + struct rb_node *mnt_first_node; /* first (leftmost) mount in the rbtree */ + }; struct user_namespace *user_ns; struct ucounts *ucounts; u64 seq; /* Sequence number to prevent loops */ - wait_queue_head_t poll; + union { + wait_queue_head_t poll; + struct rcu_head mnt_ns_rcu; + }; + u64 seq_origin; /* Sequence number of origin mount namespace */ u64 event; +#ifdef CONFIG_FSNOTIFY + __u32 n_fsnotify_mask; + struct fsnotify_mark_connector __rcu *n_fsnotify_marks; +#endif unsigned int nr_mounts; /* # of mounts in the namespace */ unsigned int pending_mounts; struct rb_node mnt_ns_tree_node; /* node in the mnt_ns_tree */ + struct list_head mnt_ns_list; /* entry in the sequential list of mounts namespace */ refcount_t passive; /* number references not pinning @mounts */ } __randomize_layout; @@ -29,7 +44,6 @@ struct mountpoint { struct hlist_node m_hash; struct dentry *m_dentry; struct hlist_head m_list; - int m_count; }; struct mount { @@ -38,6 +52,7 @@ struct mount { struct dentry *mnt_mountpoint; struct vfsmount mnt; union { + struct rb_node mnt_node; /* node in the ns->mounts rbtree */ struct rcu_head mnt_rcu; struct llist_node mnt_llist; }; @@ -51,14 +66,11 @@ struct mount { struct list_head mnt_child; /* and going through their mnt_child */ struct list_head mnt_instance; /* mount instance on sb->s_mounts */ const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ - union { - struct rb_node mnt_node; /* Under ns->mounts */ - struct list_head mnt_list; - }; + struct list_head mnt_list; struct list_head mnt_expire; /* link in fs-specific expiry list */ struct list_head mnt_share; /* circular list of shared mounts */ - struct list_head mnt_slave_list;/* list of slave mounts */ - struct list_head mnt_slave; /* slave list entry */ + struct hlist_head mnt_slave_list;/* list of slave mounts */ + struct hlist_node mnt_slave; /* slave list entry */ struct mount *mnt_master; /* slave is on master->mnt_slave_list */ struct mnt_namespace *mnt_ns; /* containing namespace */ struct mountpoint *mnt_mp; /* where is it mounted */ @@ -66,19 +78,38 @@ struct mount { struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */ struct hlist_node mnt_umount; }; - struct list_head mnt_umounting; /* list entry for umount propagation */ #ifdef CONFIG_FSNOTIFY struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks; __u32 mnt_fsnotify_mask; + struct list_head to_notify; /* need to queue notification */ + struct mnt_namespace *prev_ns; /* previous namespace (NULL if none) */ #endif + int mnt_t_flags; /* namespace_sem-protected flags */ int mnt_id; /* mount identifier, reused */ u64 mnt_id_unique; /* mount ID unique until reboot */ int mnt_group_id; /* peer group identifier */ int mnt_expiry_mark; /* true if marked for expiry */ struct hlist_head mnt_pins; struct hlist_head mnt_stuck_children; + struct mount *overmount; /* mounted on ->mnt_root */ } __randomize_layout; +enum { + T_SHARED = 1, /* mount is shared */ + T_UNBINDABLE = 2, /* mount is unbindable */ + T_MARKED = 4, /* internal mark for propagate_... */ + T_UMOUNT_CANDIDATE = 8, /* for propagate_umount */ + + /* + * T_SHARED_MASK is the set of flags that should be cleared when a + * mount becomes shared. Currently, this is only the flag that says a + * mount cannot be bind mounted, since this is how we create a mount + * that shares events with another mount. If you add a new T_* + * flag, consider how it interacts with shared mounts. + */ + T_SHARED_MASK = T_UNBINDABLE, +}; + #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */ static inline struct mount *real_mount(struct vfsmount *mnt) @@ -86,7 +117,7 @@ static inline struct mount *real_mount(struct vfsmount *mnt) return container_of(mnt, struct mount, mnt); } -static inline int mnt_has_parent(struct mount *mnt) +static inline int mnt_has_parent(const struct mount *mnt) { return mnt != mnt->mnt_parent; } @@ -131,8 +162,8 @@ struct proc_mounts { extern const struct seq_operations mounts_op; -extern bool __is_local_mountpoint(struct dentry *dentry); -static inline bool is_local_mountpoint(struct dentry *dentry) +extern bool __is_local_mountpoint(const struct dentry *dentry); +static inline bool is_local_mountpoint(const struct dentry *dentry) { if (!d_mountpoint(dentry)) return false; @@ -145,25 +176,58 @@ static inline bool is_anon_ns(struct mnt_namespace *ns) return ns->seq == 0; } -static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list) +static inline bool anon_ns_root(const struct mount *m) { - WARN_ON(!(mnt->mnt.mnt_flags & MNT_ONRB)); - mnt->mnt.mnt_flags &= ~MNT_ONRB; - rb_erase(&mnt->mnt_node, &mnt->mnt_ns->mounts); - list_add_tail(&mnt->mnt_list, dt_list); + struct mnt_namespace *ns = READ_ONCE(m->mnt_ns); + + return !IS_ERR_OR_NULL(ns) && is_anon_ns(ns) && m == ns->root; } -bool has_locked_children(struct mount *mnt, struct dentry *dentry); -struct mnt_namespace *__lookup_next_mnt_ns(struct mnt_namespace *mnt_ns, bool previous); -static inline struct mnt_namespace *lookup_next_mnt_ns(struct mnt_namespace *mntns) +static inline bool mnt_ns_attached(const struct mount *mnt) +{ + return !RB_EMPTY_NODE(&mnt->mnt_node); +} + +static inline bool mnt_ns_empty(const struct mnt_namespace *ns) { - return __lookup_next_mnt_ns(mntns, false); + return RB_EMPTY_ROOT(&ns->mounts); } -static inline struct mnt_namespace *lookup_prev_mnt_ns(struct mnt_namespace *mntns) + +static inline void move_from_ns(struct mount *mnt) { - return __lookup_next_mnt_ns(mntns, true); + struct mnt_namespace *ns = mnt->mnt_ns; + WARN_ON(!mnt_ns_attached(mnt)); + if (ns->mnt_last_node == &mnt->mnt_node) + ns->mnt_last_node = rb_prev(&mnt->mnt_node); + if (ns->mnt_first_node == &mnt->mnt_node) + ns->mnt_first_node = rb_next(&mnt->mnt_node); + rb_erase(&mnt->mnt_node, &ns->mounts); + RB_CLEAR_NODE(&mnt->mnt_node); } + +bool has_locked_children(struct mount *mnt, struct dentry *dentry); +struct mnt_namespace *get_sequential_mnt_ns(struct mnt_namespace *mnt_ns, + bool previous); + static inline struct mnt_namespace *to_mnt_ns(struct ns_common *ns) { return container_of(ns, struct mnt_namespace, ns); } + +#ifdef CONFIG_FSNOTIFY +static inline void mnt_notify_add(struct mount *m) +{ + /* Optimize the case where there are no watches */ + if ((m->mnt_ns && m->mnt_ns->n_fsnotify_marks) || + (m->prev_ns && m->prev_ns->n_fsnotify_marks)) + list_add_tail(&m->to_notify, ¬ify_list); + else + m->prev_ns = m->mnt_ns; +} +#else +static inline void mnt_notify_add(struct mount *m) +{ +} +#endif + +struct mnt_namespace *mnt_ns_from_dentry(struct dentry *dentry); |