mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-19 18:53:52 +08:00
858d72ead4
When a task enters a new namespace via a clone() or unshare(), a new cgroup is created and the task moves into it. This version names cgroups which are automatically created using cgroup_clone() as "node_<pid>" where pid is the pid of the unsharing or cloned process. (Thanks Pavel for the idea) This is safe because if the process unshares again, it will create /cgroups/(...)/node_<pid>/node_<pid> The only possibilities (AFAICT) for a -EEXIST on unshare are 1. pid wraparound 2. a process fails an unshare, then tries again. Case 1 is unlikely enough that I ignore it (at least for now). In case 2, the node_<pid> will be empty and can be rmdir'ed to make the subsequent unshare() succeed. Changelog: Name cloned cgroups as "node_<pid>". [clg@fr.ibm.com: fix order of cgroup subsystems in init/Kconfig] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
#ifndef _LINUX_NSPROXY_H
|
|
#define _LINUX_NSPROXY_H
|
|
|
|
#include <linux/spinlock.h>
|
|
#include <linux/sched.h>
|
|
|
|
struct mnt_namespace;
|
|
struct uts_namespace;
|
|
struct ipc_namespace;
|
|
struct pid_namespace;
|
|
|
|
/*
|
|
* A structure to contain pointers to all per-process
|
|
* namespaces - fs (mount), uts, network, sysvipc, etc.
|
|
*
|
|
* 'count' is the number of tasks holding a reference.
|
|
* The count for each namespace, then, will be the number
|
|
* of nsproxies pointing to it, not the number of tasks.
|
|
*
|
|
* The nsproxy is shared by tasks which share all namespaces.
|
|
* As soon as a single namespace is cloned or unshared, the
|
|
* nsproxy is copied.
|
|
*/
|
|
struct nsproxy {
|
|
atomic_t count;
|
|
struct uts_namespace *uts_ns;
|
|
struct ipc_namespace *ipc_ns;
|
|
struct mnt_namespace *mnt_ns;
|
|
struct pid_namespace *pid_ns;
|
|
struct user_namespace *user_ns;
|
|
struct net *net_ns;
|
|
};
|
|
extern struct nsproxy init_nsproxy;
|
|
|
|
int copy_namespaces(unsigned long flags, struct task_struct *tsk);
|
|
void get_task_namespaces(struct task_struct *tsk);
|
|
void free_nsproxy(struct nsproxy *ns);
|
|
int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **,
|
|
struct fs_struct *);
|
|
|
|
static inline void put_nsproxy(struct nsproxy *ns)
|
|
{
|
|
if (atomic_dec_and_test(&ns->count)) {
|
|
free_nsproxy(ns);
|
|
}
|
|
}
|
|
|
|
static inline void exit_task_namespaces(struct task_struct *p)
|
|
{
|
|
struct nsproxy *ns = p->nsproxy;
|
|
if (ns) {
|
|
task_lock(p);
|
|
p->nsproxy = NULL;
|
|
task_unlock(p);
|
|
put_nsproxy(ns);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_CGROUP_NS
|
|
int ns_cgroup_clone(struct task_struct *tsk);
|
|
#else
|
|
static inline int ns_cgroup_clone(struct task_struct *tsk) { return 0; }
|
|
#endif
|
|
|
|
#endif
|