Commit 9a575a92 authored by Cedric Le Goater's avatar Cedric Le Goater Committed by Linus Torvalds
Browse files

[PATCH] to nsproxy 



Add the pid namespace framework to the nsproxy object.  The copy of the pid
namespace only increases the refcount on the global pid namespace,
init_pid_ns, and unshare is not implemented.

There is no configuration option to activate or deactivate this feature
because this not relevant for the moment.

Signed-off-by: default avatarCedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 61a58c6c

include/linux/init_task.h

+2 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/utsname.h>

#include <linux/lockdep.h>

#include <linux/ipc.h>

#include <linux/pid_namespace.h>



#define INIT_FDTABLE \

{							\
@@ -73,6 +74,7 @@ 


extern struct nsproxy init_nsproxy;

#define INIT_NSPROXY(nsproxy) {						\

	.pid_ns		= &init_pid_ns,					\

	.count		= ATOMIC_INIT(1),				\

	.nslock		= __SPIN_LOCK_UNLOCKED(nsproxy.nslock),		\

	.id		= 0,						\

include/linux/nsproxy.h

+2 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
struct mnt_namespace;

struct uts_namespace;

struct ipc_namespace;

struct pid_namespace;



/*

 * A structure to contain pointers to all per-process
@@ -27,6 +28,7 @@ struct nsproxy { 
	struct uts_namespace *uts_ns;

	struct ipc_namespace *ipc_ns;

	struct mnt_namespace *mnt_ns;

	struct pid_namespace *pid_ns;

};

extern struct nsproxy init_nsproxy;

include/linux/pid_namespace.h

+18 −2
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 
#include <linux/mm.h>

#include <linux/threads.h>

#include <linux/pid.h>

#include <linux/nsproxy.h>

#include <linux/kref.h>



struct pidmap {

       atomic_t nr_free;
@@ -14,10 +16,24 @@ struct pidmap { 
#define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)



struct pid_namespace {

	struct kref kref;

	struct pidmap pidmap[PIDMAP_ENTRIES];

	int last_pid;

};



extern struct pid_namespace init_pid_ns;



static inline void get_pid_ns(struct pid_namespace *ns)

{

	kref_get(&ns->kref);

}



extern int copy_pid_ns(int flags, struct task_struct *tsk);

extern void free_pid_ns(struct kref *kref);



static inline void put_pid_ns(struct pid_namespace *ns)

{

	kref_put(&ns->kref, free_pid_ns);

}



#endif /* _LINUX_PID_NS_H */

kernel/nsproxy.c

+19 −7
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/init_task.h>

#include <linux/mnt_namespace.h>

#include <linux/utsname.h>

#include <linux/pid_namespace.h>



struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
@@ -68,6 +69,8 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig) 
			get_uts_ns(ns->uts_ns);

		if (ns->ipc_ns)

			get_ipc_ns(ns->ipc_ns);

		if (ns->pid_ns)

			get_pid_ns(ns->pid_ns);

	}



	return ns;
@@ -111,10 +114,17 @@ int copy_namespaces(int flags, struct task_struct *tsk) 
	if (err)

		goto out_ipc;



	err = copy_pid_ns(flags, tsk);

	if (err)

		goto out_pid;



out:

	put_nsproxy(old_ns);

	return err;



out_pid:

	if (new_ns->ipc_ns)

		put_ipc_ns(new_ns->ipc_ns);

out_ipc:

	if (new_ns->uts_ns)

		put_uts_ns(new_ns->uts_ns);
@@ -135,5 +145,7 @@ void free_nsproxy(struct nsproxy *ns) 
		put_uts_ns(ns->uts_ns);

	if (ns->ipc_ns)

		put_ipc_ns(ns->ipc_ns);

	if (ns->pid_ns)

		put_pid_ns(ns->pid_ns);

	kfree(ns);

}

kernel/pid.c

+23 −0
Original line number Diff line number Diff line
@@ -59,6 +59,9 @@ static inline int mk_pid(struct pid_namespace *pid_ns, 
 * the scheme scales to up to 4 million PIDs, runtime.

 */

struct pid_namespace init_pid_ns = {

	.kref = {

		.refcount       = ATOMIC_INIT(2),

	},

	.pidmap = {

		[ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL }

	},
@@ -356,6 +359,26 @@ struct pid *find_ge_pid(int nr) 
}

EXPORT_SYMBOL_GPL(find_get_pid);



int copy_pid_ns(int flags, struct task_struct *tsk)

{

	struct pid_namespace *old_ns = tsk->nsproxy->pid_ns;

	int err = 0;



	if (!old_ns)

		return 0;



	get_pid_ns(old_ns);

	return err;

}



void free_pid_ns(struct kref *kref)

{

	struct pid_namespace *ns;



	ns = container_of(kref, struct pid_namespace, kref);

	kfree(ns);

}



/*

 * The pid hash table is scaled according to the amount of memory in the

 * machine.  From a minimum of 16 slots up to 4096 slots at one gigabyte or

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