Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ns: move namespace types into separate header
Add a dedicated header for namespace types.
Link: https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-1-e8a9264e0fb9@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
+206
-195
+205
include/linux/ns/ns_common_types.h
+205
include/linux/ns/ns_common_types.h
···
1
+
/* SPDX-License-Identifier: GPL-2.0 */
2
+
#ifndef _LINUX_NS_COMMON_TYPES_H
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#define _LINUX_NS_COMMON_TYPES_H
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#include <linux/atomic.h>
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#include <linux/rbtree.h>
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#include <linux/refcount.h>
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#include <linux/types.h>
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struct cgroup_namespace;
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struct dentry;
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struct ipc_namespace;
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struct mnt_namespace;
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struct net;
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struct pid_namespace;
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struct proc_ns_operations;
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struct time_namespace;
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struct user_namespace;
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struct uts_namespace;
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extern struct cgroup_namespace init_cgroup_ns;
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extern struct ipc_namespace init_ipc_ns;
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extern struct mnt_namespace init_mnt_ns;
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extern struct net init_net;
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extern struct pid_namespace init_pid_ns;
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extern struct time_namespace init_time_ns;
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extern struct user_namespace init_user_ns;
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extern struct uts_namespace init_uts_ns;
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extern const struct proc_ns_operations cgroupns_operations;
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extern const struct proc_ns_operations ipcns_operations;
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extern const struct proc_ns_operations mntns_operations;
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extern const struct proc_ns_operations netns_operations;
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extern const struct proc_ns_operations pidns_operations;
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extern const struct proc_ns_operations pidns_for_children_operations;
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extern const struct proc_ns_operations timens_operations;
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extern const struct proc_ns_operations timens_for_children_operations;
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extern const struct proc_ns_operations userns_operations;
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extern const struct proc_ns_operations utsns_operations;
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/*
42
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* Namespace lifetimes are managed via a two-tier reference counting model:
43
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*
44
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* (1) __ns_ref (refcount_t): Main reference count tracking memory
45
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* lifetime. Controls when the namespace structure itself is freed.
46
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* It also pins the namespace on the namespace trees whereas (2)
47
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* only regulates their visibility to userspace.
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*
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* (2) __ns_ref_active (atomic_t): Reference count tracking active users.
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* Controls visibility of the namespace in the namespace trees.
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* Any live task that uses the namespace (via nsproxy or cred) holds
52
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* an active reference. Any open file descriptor or bind-mount of
53
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* the namespace holds an active reference. Once all tasks have
54
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* called exited their namespaces and all file descriptors and
55
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* bind-mounts have been released the active reference count drops
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* to zero and the namespace becomes inactive. IOW, the namespace
57
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* cannot be listed or opened via file handles anymore.
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*
59
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* Note that it is valid to transition from active to inactive and
60
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* back from inactive to active e.g., when resurrecting an inactive
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* namespace tree via the SIOCGSKNS ioctl().
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*
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* Relationship and lifecycle states:
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*
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* - Active (__ns_ref_active > 0):
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* Namespace is actively used and visible to userspace. The namespace
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* can be reopened via /proc/<pid>/ns/<ns_type>, via namespace file
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* handles, or discovered via listns().
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+
*
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* - Inactive (__ns_ref_active == 0, __ns_ref > 0):
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* No tasks are actively using the namespace and it isn't pinned by
72
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* any bind-mounts or open file descriptors anymore. But the namespace
73
+
* is still kept alive by internal references. For example, the user
74
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* namespace could be pinned by an open file through file->f_cred
75
+
* references when one of the now defunct tasks had opened a file and
76
+
* handed the file descriptor off to another process via a UNIX
77
+
* sockets. Such references keep the namespace structure alive through
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* __ns_ref but will not hold an active reference.
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*
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* - Destroyed (__ns_ref == 0):
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* No references remain. The namespace is removed from the tree and freed.
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*
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* State transitions:
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*
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* Active -> Inactive:
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* When the last task using the namespace exits it drops its active
87
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* references to all namespaces. However, user and pid namespaces
88
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* remain accessible until the task has been reaped.
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*
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* Inactive -> Active:
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* An inactive namespace tree might be resurrected due to e.g., the
92
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* SIOCGSKNS ioctl() on a socket.
93
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*
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* Inactive -> Destroyed:
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* When __ns_ref drops to zero the namespace is removed from the
96
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* namespaces trees and the memory is freed (after RCU grace period).
97
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*
98
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* Initial namespaces:
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* Boot-time namespaces (init_net, init_pid_ns, etc.) start with
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* __ns_ref_active = 1 and remain active forever.
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*/
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struct ns_common {
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u32 ns_type;
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struct dentry *stashed;
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const struct proc_ns_operations *ops;
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unsigned int inum;
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refcount_t __ns_ref; /* do not use directly */
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union {
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struct {
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u64 ns_id;
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struct /* global namespace rbtree and list */ {
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struct rb_node ns_unified_tree_node;
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struct list_head ns_unified_list_node;
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};
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struct /* per type rbtree and list */ {
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struct rb_node ns_tree_node;
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struct list_head ns_list_node;
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};
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struct /* namespace ownership rbtree and list */ {
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struct rb_root ns_owner_tree; /* rbtree of namespaces owned by this namespace */
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struct list_head ns_owner; /* list of namespaces owned by this namespace */
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struct rb_node ns_owner_tree_node; /* node in the owner namespace's rbtree */
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struct list_head ns_owner_entry; /* node in the owner namespace's ns_owned list */
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};
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atomic_t __ns_ref_active; /* do not use directly */
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};
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struct rcu_head ns_rcu;
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};
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};
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#define to_ns_common(__ns) \
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_Generic((__ns), \
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struct cgroup_namespace *: &(__ns)->ns, \
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const struct cgroup_namespace *: &(__ns)->ns, \
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struct ipc_namespace *: &(__ns)->ns, \
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const struct ipc_namespace *: &(__ns)->ns, \
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struct mnt_namespace *: &(__ns)->ns, \
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const struct mnt_namespace *: &(__ns)->ns, \
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struct net *: &(__ns)->ns, \
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const struct net *: &(__ns)->ns, \
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struct pid_namespace *: &(__ns)->ns, \
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const struct pid_namespace *: &(__ns)->ns, \
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struct time_namespace *: &(__ns)->ns, \
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const struct time_namespace *: &(__ns)->ns, \
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struct user_namespace *: &(__ns)->ns, \
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const struct user_namespace *: &(__ns)->ns, \
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struct uts_namespace *: &(__ns)->ns, \
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const struct uts_namespace *: &(__ns)->ns)
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#define ns_init_inum(__ns) \
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_Generic((__ns), \
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struct cgroup_namespace *: CGROUP_NS_INIT_INO, \
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struct ipc_namespace *: IPC_NS_INIT_INO, \
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struct mnt_namespace *: MNT_NS_INIT_INO, \
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struct net *: NET_NS_INIT_INO, \
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struct pid_namespace *: PID_NS_INIT_INO, \
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struct time_namespace *: TIME_NS_INIT_INO, \
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struct user_namespace *: USER_NS_INIT_INO, \
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struct uts_namespace *: UTS_NS_INIT_INO)
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#define ns_init_ns(__ns) \
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_Generic((__ns), \
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struct cgroup_namespace *: &init_cgroup_ns, \
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struct ipc_namespace *: &init_ipc_ns, \
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struct mnt_namespace *: &init_mnt_ns, \
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struct net *: &init_net, \
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struct pid_namespace *: &init_pid_ns, \
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struct time_namespace *: &init_time_ns, \
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struct user_namespace *: &init_user_ns, \
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struct uts_namespace *: &init_uts_ns)
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#define ns_init_id(__ns) \
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_Generic((__ns), \
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struct cgroup_namespace *: CGROUP_NS_INIT_ID, \
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struct ipc_namespace *: IPC_NS_INIT_ID, \
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struct mnt_namespace *: MNT_NS_INIT_ID, \
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struct net *: NET_NS_INIT_ID, \
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struct pid_namespace *: PID_NS_INIT_ID, \
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struct time_namespace *: TIME_NS_INIT_ID, \
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struct user_namespace *: USER_NS_INIT_ID, \
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struct uts_namespace *: UTS_NS_INIT_ID)
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#define to_ns_operations(__ns) \
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_Generic((__ns), \
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struct cgroup_namespace *: (IS_ENABLED(CONFIG_CGROUPS) ? &cgroupns_operations : NULL), \
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struct ipc_namespace *: (IS_ENABLED(CONFIG_IPC_NS) ? &ipcns_operations : NULL), \
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struct mnt_namespace *: &mntns_operations, \
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struct net *: (IS_ENABLED(CONFIG_NET_NS) ? &netns_operations : NULL), \
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struct pid_namespace *: (IS_ENABLED(CONFIG_PID_NS) ? &pidns_operations : NULL), \
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struct time_namespace *: (IS_ENABLED(CONFIG_TIME_NS) ? &timens_operations : NULL), \
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struct user_namespace *: (IS_ENABLED(CONFIG_USER_NS) ? &userns_operations : NULL), \
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struct uts_namespace *: (IS_ENABLED(CONFIG_UTS_NS) ? &utsns_operations : NULL))
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#define ns_common_type(__ns) \
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_Generic((__ns), \
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struct cgroup_namespace *: CLONE_NEWCGROUP, \
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struct ipc_namespace *: CLONE_NEWIPC, \
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struct mnt_namespace *: CLONE_NEWNS, \
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struct net *: CLONE_NEWNET, \
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struct pid_namespace *: CLONE_NEWPID, \
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struct time_namespace *: CLONE_NEWTIME, \
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struct user_namespace *: CLONE_NEWUSER, \
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struct uts_namespace *: CLONE_NEWUTS)
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#endif /* _LINUX_NS_COMMON_TYPES_H */
+1
-195
include/linux/ns_common.h
+1
-195
include/linux/ns_common.h
···
2
2
#ifndef _LINUX_NS_COMMON_H
3
3
#define _LINUX_NS_COMMON_H
4
4
5
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#include <linux/ns/ns_common_types.h>
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#include <linux/refcount.h>
6
-
#include <linux/rbtree.h>
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#include <linux/vfsdebug.h>
8
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#include <uapi/linux/sched.h>
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#include <uapi/linux/nsfs.h>
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struct proc_ns_operations;
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struct cgroup_namespace;
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struct ipc_namespace;
15
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struct mnt_namespace;
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struct net;
17
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struct pid_namespace;
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struct time_namespace;
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struct user_namespace;
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struct uts_namespace;
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-
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extern struct cgroup_namespace init_cgroup_ns;
23
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extern struct ipc_namespace init_ipc_ns;
24
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extern struct mnt_namespace init_mnt_ns;
25
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extern struct net init_net;
26
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extern struct pid_namespace init_pid_ns;
27
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extern struct time_namespace init_time_ns;
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extern struct user_namespace init_user_ns;
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extern struct uts_namespace init_uts_ns;
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-
31
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extern const struct proc_ns_operations netns_operations;
32
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extern const struct proc_ns_operations utsns_operations;
33
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extern const struct proc_ns_operations ipcns_operations;
34
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extern const struct proc_ns_operations pidns_operations;
35
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extern const struct proc_ns_operations pidns_for_children_operations;
36
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extern const struct proc_ns_operations userns_operations;
37
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extern const struct proc_ns_operations mntns_operations;
38
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extern const struct proc_ns_operations cgroupns_operations;
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extern const struct proc_ns_operations timens_operations;
40
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extern const struct proc_ns_operations timens_for_children_operations;
41
-
42
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/*
43
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* Namespace lifetimes are managed via a two-tier reference counting model:
44
-
*
45
-
* (1) __ns_ref (refcount_t): Main reference count tracking memory
46
-
* lifetime. Controls when the namespace structure itself is freed.
47
-
* It also pins the namespace on the namespace trees whereas (2)
48
-
* only regulates their visibility to userspace.
49
-
*
50
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* (2) __ns_ref_active (atomic_t): Reference count tracking active users.
51
-
* Controls visibility of the namespace in the namespace trees.
52
-
* Any live task that uses the namespace (via nsproxy or cred) holds
53
-
* an active reference. Any open file descriptor or bind-mount of
54
-
* the namespace holds an active reference. Once all tasks have
55
-
* called exited their namespaces and all file descriptors and
56
-
* bind-mounts have been released the active reference count drops
57
-
* to zero and the namespace becomes inactive. IOW, the namespace
58
-
* cannot be listed or opened via file handles anymore.
59
-
*
60
-
* Note that it is valid to transition from active to inactive and
61
-
* back from inactive to active e.g., when resurrecting an inactive
62
-
* namespace tree via the SIOCGSKNS ioctl().
63
-
*
64
-
* Relationship and lifecycle states:
65
-
*
66
-
* - Active (__ns_ref_active > 0):
67
-
* Namespace is actively used and visible to userspace. The namespace
68
-
* can be reopened via /proc/<pid>/ns/<ns_type>, via namespace file
69
-
* handles, or discovered via listns().
70
-
*
71
-
* - Inactive (__ns_ref_active == 0, __ns_ref > 0):
72
-
* No tasks are actively using the namespace and it isn't pinned by
73
-
* any bind-mounts or open file descriptors anymore. But the namespace
74
-
* is still kept alive by internal references. For example, the user
75
-
* namespace could be pinned by an open file through file->f_cred
76
-
* references when one of the now defunct tasks had opened a file and
77
-
* handed the file descriptor off to another process via a UNIX
78
-
* sockets. Such references keep the namespace structure alive through
79
-
* __ns_ref but will not hold an active reference.
80
-
*
81
-
* - Destroyed (__ns_ref == 0):
82
-
* No references remain. The namespace is removed from the tree and freed.
83
-
*
84
-
* State transitions:
85
-
*
86
-
* Active -> Inactive:
87
-
* When the last task using the namespace exits it drops its active
88
-
* references to all namespaces. However, user and pid namespaces
89
-
* remain accessible until the task has been reaped.
90
-
*
91
-
* Inactive -> Active:
92
-
* An inactive namespace tree might be resurrected due to e.g., the
93
-
* SIOCGSKNS ioctl() on a socket.
94
-
*
95
-
* Inactive -> Destroyed:
96
-
* When __ns_ref drops to zero the namespace is removed from the
97
-
* namespaces trees and the memory is freed (after RCU grace period).
98
-
*
99
-
* Initial namespaces:
100
-
* Boot-time namespaces (init_net, init_pid_ns, etc.) start with
101
-
* __ns_ref_active = 1 and remain active forever.
102
-
*/
103
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struct ns_common {
104
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u32 ns_type;
105
-
struct dentry *stashed;
106
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const struct proc_ns_operations *ops;
107
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unsigned int inum;
108
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refcount_t __ns_ref; /* do not use directly */
109
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union {
110
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struct {
111
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u64 ns_id;
112
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struct /* global namespace rbtree and list */ {
113
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struct rb_node ns_unified_tree_node;
114
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struct list_head ns_unified_list_node;
115
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};
116
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struct /* per type rbtree and list */ {
117
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struct rb_node ns_tree_node;
118
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struct list_head ns_list_node;
119
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};
120
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struct /* namespace ownership rbtree and list */ {
121
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struct rb_root ns_owner_tree; /* rbtree of namespaces owned by this namespace */
122
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struct list_head ns_owner; /* list of namespaces owned by this namespace */
123
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struct rb_node ns_owner_tree_node; /* node in the owner namespace's rbtree */
124
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struct list_head ns_owner_entry; /* node in the owner namespace's ns_owned list */
125
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};
126
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atomic_t __ns_ref_active; /* do not use directly */
127
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};
128
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struct rcu_head ns_rcu;
129
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};
130
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};
131
10
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11
bool is_current_namespace(struct ns_common *ns);
133
12
int __ns_common_init(struct ns_common *ns, u32 ns_type, const struct proc_ns_operations *ops, int inum);
···
26
147
return ns->ns_id <= NS_LAST_INIT_ID;
27
148
}
28
149
29
-
#define to_ns_common(__ns) \
30
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_Generic((__ns), \
31
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struct cgroup_namespace *: &(__ns)->ns, \
32
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const struct cgroup_namespace *: &(__ns)->ns, \
33
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struct ipc_namespace *: &(__ns)->ns, \
34
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const struct ipc_namespace *: &(__ns)->ns, \
35
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struct mnt_namespace *: &(__ns)->ns, \
36
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const struct mnt_namespace *: &(__ns)->ns, \
37
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struct net *: &(__ns)->ns, \
38
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const struct net *: &(__ns)->ns, \
39
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struct pid_namespace *: &(__ns)->ns, \
40
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const struct pid_namespace *: &(__ns)->ns, \
41
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struct time_namespace *: &(__ns)->ns, \
42
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const struct time_namespace *: &(__ns)->ns, \
43
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struct user_namespace *: &(__ns)->ns, \
44
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const struct user_namespace *: &(__ns)->ns, \
45
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struct uts_namespace *: &(__ns)->ns, \
46
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const struct uts_namespace *: &(__ns)->ns)
47
-
48
-
#define ns_init_inum(__ns) \
49
-
_Generic((__ns), \
50
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struct cgroup_namespace *: CGROUP_NS_INIT_INO, \
51
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struct ipc_namespace *: IPC_NS_INIT_INO, \
52
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struct mnt_namespace *: MNT_NS_INIT_INO, \
53
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struct net *: NET_NS_INIT_INO, \
54
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struct pid_namespace *: PID_NS_INIT_INO, \
55
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struct time_namespace *: TIME_NS_INIT_INO, \
56
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struct user_namespace *: USER_NS_INIT_INO, \
57
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struct uts_namespace *: UTS_NS_INIT_INO)
58
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59
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#define ns_init_ns(__ns) \
60
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_Generic((__ns), \
61
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struct cgroup_namespace *: &init_cgroup_ns, \
62
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struct ipc_namespace *: &init_ipc_ns, \
63
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struct mnt_namespace *: &init_mnt_ns, \
64
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struct net *: &init_net, \
65
-
struct pid_namespace *: &init_pid_ns, \
66
-
struct time_namespace *: &init_time_ns, \
67
-
struct user_namespace *: &init_user_ns, \
68
-
struct uts_namespace *: &init_uts_ns)
69
-
70
-
#define ns_init_id(__ns) \
71
-
_Generic((__ns), \
72
-
struct cgroup_namespace *: CGROUP_NS_INIT_ID, \
73
-
struct ipc_namespace *: IPC_NS_INIT_ID, \
74
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struct mnt_namespace *: MNT_NS_INIT_ID, \
75
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struct net *: NET_NS_INIT_ID, \
76
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struct pid_namespace *: PID_NS_INIT_ID, \
77
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struct time_namespace *: TIME_NS_INIT_ID, \
78
-
struct user_namespace *: USER_NS_INIT_ID, \
79
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struct uts_namespace *: UTS_NS_INIT_ID)
80
-
81
-
#define to_ns_operations(__ns) \
82
-
_Generic((__ns), \
83
-
struct cgroup_namespace *: (IS_ENABLED(CONFIG_CGROUPS) ? &cgroupns_operations : NULL), \
84
-
struct ipc_namespace *: (IS_ENABLED(CONFIG_IPC_NS) ? &ipcns_operations : NULL), \
85
-
struct mnt_namespace *: &mntns_operations, \
86
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struct net *: (IS_ENABLED(CONFIG_NET_NS) ? &netns_operations : NULL), \
87
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struct pid_namespace *: (IS_ENABLED(CONFIG_PID_NS) ? &pidns_operations : NULL), \
88
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struct time_namespace *: (IS_ENABLED(CONFIG_TIME_NS) ? &timens_operations : NULL), \
89
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struct user_namespace *: (IS_ENABLED(CONFIG_USER_NS) ? &userns_operations : NULL), \
90
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struct uts_namespace *: (IS_ENABLED(CONFIG_UTS_NS) ? &utsns_operations : NULL))
91
-
92
-
#define ns_common_type(__ns) \
93
-
_Generic((__ns), \
94
-
struct cgroup_namespace *: CLONE_NEWCGROUP, \
95
-
struct ipc_namespace *: CLONE_NEWIPC, \
96
-
struct mnt_namespace *: CLONE_NEWNS, \
97
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struct net *: CLONE_NEWNET, \
98
-
struct pid_namespace *: CLONE_NEWPID, \
99
-
struct time_namespace *: CLONE_NEWTIME, \
100
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struct user_namespace *: CLONE_NEWUSER, \
101
-
struct uts_namespace *: CLONE_NEWUTS)
102
150
103
151
#define NS_COMMON_INIT(nsname, refs) \
104
152
{ \