diff options
Diffstat (limited to 'include/linux/ns_common.h')
| -rw-r--r-- | include/linux/ns_common.h | 233 |
1 files changed, 115 insertions, 118 deletions
diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index f5b68b8abb54..825f5865bfc5 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -2,122 +2,44 @@ #ifndef _LINUX_NS_COMMON_H #define _LINUX_NS_COMMON_H +#include <linux/ns/ns_common_types.h> #include <linux/refcount.h> -#include <linux/rbtree.h> +#include <linux/vfsdebug.h> #include <uapi/linux/sched.h> +#include <uapi/linux/nsfs.h> -struct proc_ns_operations; - -struct cgroup_namespace; -struct ipc_namespace; -struct mnt_namespace; -struct net; -struct pid_namespace; -struct time_namespace; -struct user_namespace; -struct uts_namespace; - -extern struct cgroup_namespace init_cgroup_ns; -extern struct ipc_namespace init_ipc_ns; -extern struct mnt_namespace init_mnt_ns; -extern struct net init_net; -extern struct pid_namespace init_pid_ns; -extern struct time_namespace init_time_ns; -extern struct user_namespace init_user_ns; -extern struct uts_namespace init_uts_ns; - -extern const struct proc_ns_operations netns_operations; -extern const struct proc_ns_operations utsns_operations; -extern const struct proc_ns_operations ipcns_operations; -extern const struct proc_ns_operations pidns_operations; -extern const struct proc_ns_operations pidns_for_children_operations; -extern const struct proc_ns_operations userns_operations; -extern const struct proc_ns_operations mntns_operations; -extern const struct proc_ns_operations cgroupns_operations; -extern const struct proc_ns_operations timens_operations; -extern const struct proc_ns_operations timens_for_children_operations; - -struct ns_common { - u32 ns_type; - struct dentry *stashed; - const struct proc_ns_operations *ops; - unsigned int inum; - refcount_t __ns_ref; /* do not use directly */ - union { - struct { - u64 ns_id; - struct rb_node ns_tree_node; - struct list_head ns_list_node; - }; - struct rcu_head ns_rcu; - }; -}; - +bool is_current_namespace(struct ns_common *ns); int __ns_common_init(struct ns_common *ns, u32 ns_type, const struct proc_ns_operations *ops, int inum); void __ns_common_free(struct ns_common *ns); +struct ns_common *__must_check ns_owner(struct ns_common *ns); + +static __always_inline bool is_ns_init_inum(const struct ns_common *ns) +{ + VFS_WARN_ON_ONCE(ns->inum == 0); + return unlikely(in_range(ns->inum, MNT_NS_INIT_INO, + IPC_NS_INIT_INO - MNT_NS_INIT_INO + 1)); +} + +static __always_inline bool is_ns_init_id(const struct ns_common *ns) +{ + VFS_WARN_ON_ONCE(ns->ns_id == 0); + return ns->ns_id <= NS_LAST_INIT_ID; +} -#define to_ns_common(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: &(__ns)->ns, \ - const struct cgroup_namespace *: &(__ns)->ns, \ - struct ipc_namespace *: &(__ns)->ns, \ - const struct ipc_namespace *: &(__ns)->ns, \ - struct mnt_namespace *: &(__ns)->ns, \ - const struct mnt_namespace *: &(__ns)->ns, \ - struct net *: &(__ns)->ns, \ - const struct net *: &(__ns)->ns, \ - struct pid_namespace *: &(__ns)->ns, \ - const struct pid_namespace *: &(__ns)->ns, \ - struct time_namespace *: &(__ns)->ns, \ - const struct time_namespace *: &(__ns)->ns, \ - struct user_namespace *: &(__ns)->ns, \ - const struct user_namespace *: &(__ns)->ns, \ - struct uts_namespace *: &(__ns)->ns, \ - const struct uts_namespace *: &(__ns)->ns) - -#define ns_init_inum(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: CGROUP_NS_INIT_INO, \ - struct ipc_namespace *: IPC_NS_INIT_INO, \ - struct mnt_namespace *: MNT_NS_INIT_INO, \ - struct net *: NET_NS_INIT_INO, \ - struct pid_namespace *: PID_NS_INIT_INO, \ - struct time_namespace *: TIME_NS_INIT_INO, \ - struct user_namespace *: USER_NS_INIT_INO, \ - struct uts_namespace *: UTS_NS_INIT_INO) - -#define ns_init_ns(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: &init_cgroup_ns, \ - struct ipc_namespace *: &init_ipc_ns, \ - struct mnt_namespace *: &init_mnt_ns, \ - struct net *: &init_net, \ - struct pid_namespace *: &init_pid_ns, \ - struct time_namespace *: &init_time_ns, \ - struct user_namespace *: &init_user_ns, \ - struct uts_namespace *: &init_uts_ns) - -#define to_ns_operations(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: (IS_ENABLED(CONFIG_CGROUPS) ? &cgroupns_operations : NULL), \ - struct ipc_namespace *: (IS_ENABLED(CONFIG_IPC_NS) ? &ipcns_operations : NULL), \ - struct mnt_namespace *: &mntns_operations, \ - struct net *: (IS_ENABLED(CONFIG_NET_NS) ? &netns_operations : NULL), \ - struct pid_namespace *: (IS_ENABLED(CONFIG_PID_NS) ? &pidns_operations : NULL), \ - struct time_namespace *: (IS_ENABLED(CONFIG_TIME_NS) ? &timens_operations : NULL), \ - struct user_namespace *: (IS_ENABLED(CONFIG_USER_NS) ? &userns_operations : NULL), \ - struct uts_namespace *: (IS_ENABLED(CONFIG_UTS_NS) ? &utsns_operations : NULL)) - -#define ns_common_type(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: CLONE_NEWCGROUP, \ - struct ipc_namespace *: CLONE_NEWIPC, \ - struct mnt_namespace *: CLONE_NEWNS, \ - struct net *: CLONE_NEWNET, \ - struct pid_namespace *: CLONE_NEWPID, \ - struct time_namespace *: CLONE_NEWTIME, \ - struct user_namespace *: CLONE_NEWUSER, \ - struct uts_namespace *: CLONE_NEWUTS) +#define NS_COMMON_INIT(nsname) \ +{ \ + .ns_type = ns_common_type(&nsname), \ + .ns_id = ns_init_id(&nsname), \ + .inum = ns_init_inum(&nsname), \ + .ops = to_ns_operations(&nsname), \ + .stashed = NULL, \ + .__ns_ref = REFCOUNT_INIT(1), \ + .__ns_ref_active = ATOMIC_INIT(1), \ + .ns_unified_node.ns_list_entry = LIST_HEAD_INIT(nsname.ns.ns_unified_node.ns_list_entry), \ + .ns_tree_node.ns_list_entry = LIST_HEAD_INIT(nsname.ns.ns_tree_node.ns_list_entry), \ + .ns_owner_node.ns_list_entry = LIST_HEAD_INIT(nsname.ns.ns_owner_node.ns_list_entry), \ + .ns_owner_root.ns_list_head = LIST_HEAD_INIT(nsname.ns.ns_owner_root.ns_list_head), \ +} #define ns_common_init(__ns) \ __ns_common_init(to_ns_common(__ns), \ @@ -133,21 +55,96 @@ void __ns_common_free(struct ns_common *ns); #define ns_common_free(__ns) __ns_common_free(to_ns_common((__ns))) +static __always_inline __must_check int __ns_ref_active_read(const struct ns_common *ns) +{ + return atomic_read(&ns->__ns_ref_active); +} + +static __always_inline __must_check int __ns_ref_read(const struct ns_common *ns) +{ + return refcount_read(&ns->__ns_ref); +} + static __always_inline __must_check bool __ns_ref_put(struct ns_common *ns) { - return refcount_dec_and_test(&ns->__ns_ref); + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) != 1); + return false; + } + if (refcount_dec_and_test(&ns->__ns_ref)) { + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns)); + return true; + } + return false; } static __always_inline __must_check bool __ns_ref_get(struct ns_common *ns) { - return refcount_inc_not_zero(&ns->__ns_ref); + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) != 1); + return true; + } + if (refcount_inc_not_zero(&ns->__ns_ref)) + return true; + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns)); + return false; } -#define ns_ref_read(__ns) refcount_read(&to_ns_common((__ns))->__ns_ref) -#define ns_ref_inc(__ns) refcount_inc(&to_ns_common((__ns))->__ns_ref) -#define ns_ref_get(__ns) __ns_ref_get(to_ns_common((__ns))) -#define ns_ref_put(__ns) __ns_ref_put(to_ns_common((__ns))) -#define ns_ref_put_and_lock(__ns, __lock) \ - refcount_dec_and_lock(&to_ns_common((__ns))->__ns_ref, (__lock)) +static __always_inline void __ns_ref_inc(struct ns_common *ns) +{ + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) != 1); + return; + } + refcount_inc(&ns->__ns_ref); +} + +static __always_inline __must_check bool __ns_ref_dec_and_lock(struct ns_common *ns, + spinlock_t *ns_lock) +{ + if (is_ns_init_id(ns)) { + VFS_WARN_ON_ONCE(__ns_ref_read(ns) != 1); + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) != 1); + return false; + } + return refcount_dec_and_lock(&ns->__ns_ref, ns_lock); +} + +#define ns_ref_read(__ns) __ns_ref_read(to_ns_common((__ns))) +#define ns_ref_inc(__ns) \ + do { if (__ns) __ns_ref_inc(to_ns_common((__ns))); } while (0) +#define ns_ref_get(__ns) \ + ((__ns) ? __ns_ref_get(to_ns_common((__ns))) : false) +#define ns_ref_put(__ns) \ + ((__ns) ? __ns_ref_put(to_ns_common((__ns))) : false) +#define ns_ref_put_and_lock(__ns, __ns_lock) \ + ((__ns) ? __ns_ref_dec_and_lock(to_ns_common((__ns)), __ns_lock) : false) + +#define ns_ref_active_read(__ns) \ + ((__ns) ? __ns_ref_active_read(to_ns_common(__ns)) : 0) + +void __ns_ref_active_put(struct ns_common *ns); + +#define ns_ref_active_put(__ns) \ + do { if (__ns) __ns_ref_active_put(to_ns_common(__ns)); } while (0) + +static __always_inline struct ns_common *__must_check ns_get_unless_inactive(struct ns_common *ns) +{ + if (!__ns_ref_active_read(ns)) { + VFS_WARN_ON_ONCE(is_ns_init_id(ns)); + return NULL; + } + if (!__ns_ref_get(ns)) + return NULL; + return ns; +} + +void __ns_ref_active_get(struct ns_common *ns); + +#define ns_ref_active_get(__ns) \ + do { if (__ns) __ns_ref_active_get(to_ns_common(__ns)); } while (0) #endif |