diff options
Diffstat (limited to 'include/linux/ns_common.h')
| -rw-r--r-- | include/linux/ns_common.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h new file mode 100644 index 000000000000..825f5865bfc5 --- /dev/null +++ b/include/linux/ns_common.h @@ -0,0 +1,150 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_NS_COMMON_H +#define _LINUX_NS_COMMON_H + +#include <linux/ns/ns_common_types.h> +#include <linux/refcount.h> +#include <linux/vfsdebug.h> +#include <uapi/linux/sched.h> +#include <uapi/linux/nsfs.h> + +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 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), \ + ns_common_type(__ns), \ + to_ns_operations(__ns), \ + (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0)) + +#define ns_common_init_inum(__ns, __inum) \ + __ns_common_init(to_ns_common(__ns), \ + ns_common_type(__ns), \ + to_ns_operations(__ns), \ + __inum) + +#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) +{ + 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) +{ + 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; +} + +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 |