Commit ae5e1b22 authored by Pavel Emelyanov's avatar Pavel Emelyanov Committed by Linus Torvalds
Browse files

namespaces: move the IPC namespace under IPC_NS option 



Currently the IPC namespace management code is spread over the ipc/*.c files.
I moved this code into ipc/namespace.c file which is compiled out when needed.

The linux/ipc_namespace.h file is used to store the prototypes of the
functions in namespace.c and the stubs for NAMESPACES=n case.  This is done
so, because the stub for copy_ipc_namespace requires the knowledge of the
CLONE_NEWIPC flag, which is in sched.h.  But the linux/ipc.h file itself in
included into many many .c files via the sys.h->sem.h sequence so adding the
sched.h into it will make all these .c depend on sched.h which is not that
good.  On the other hand the knowledge about the namespaces stuff is required
in 4 .c files only.

Besides, this patch compiles out some auxiliary functions from ipc/sem.c,
msg.c and shm.c files.  It turned out that moving these functions into
namespaces.c is not that easy because they use many other calls and macros
from the original file.  Moving them would make this patch complicated.  On
the other hand all these functions can be consolidated, so I will send a
separate patch doing this a bit later.

Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 58bfdd6d

include/linux/ipc.h

+0 −52
Original line number Diff line number Diff line
@@ -100,58 +100,6 @@ struct kern_ipc_perm 
	void		*security;

};



struct ipc_ids;

struct ipc_namespace {

	struct kref	kref;

	struct ipc_ids	*ids[3];



	int		sem_ctls[4];

	int		used_sems;



	int		msg_ctlmax;

	int		msg_ctlmnb;

	int		msg_ctlmni;

	atomic_t	msg_bytes;

	atomic_t	msg_hdrs;



	size_t		shm_ctlmax;

	size_t		shm_ctlall;

	int		shm_ctlmni;

	int		shm_tot;

};



extern struct ipc_namespace init_ipc_ns;



#ifdef CONFIG_SYSVIPC

#define INIT_IPC_NS(ns)		.ns		= &init_ipc_ns,

extern void free_ipc_ns(struct kref *kref);

extern struct ipc_namespace *copy_ipcs(unsigned long flags,

						struct ipc_namespace *ns);

#else

#define INIT_IPC_NS(ns)

static inline struct ipc_namespace *copy_ipcs(unsigned long flags,

						struct ipc_namespace *ns)

{

	return ns;

}

#endif



static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)

{

#ifdef CONFIG_SYSVIPC

	if (ns)

		kref_get(&ns->kref);

#endif

	return ns;

}



static inline void put_ipc_ns(struct ipc_namespace *ns)

{

#ifdef CONFIG_SYSVIPC

	kref_put(&ns->kref, free_ipc_ns);

#endif

}



#endif /* __KERNEL__ */



#endif /* _LINUX_IPC_H */

include/linux/ipc_namespace.h

0 → 100644
+69 −0
Original line number Diff line number Diff line 
#ifndef __IPC_NAMESPACE_H__

#define __IPC_NAMESPACE_H__



#include <linux/err.h>



struct ipc_ids;

struct ipc_namespace {

	struct kref	kref;

	struct ipc_ids	*ids[3];



	int		sem_ctls[4];

	int		used_sems;



	int		msg_ctlmax;

	int		msg_ctlmnb;

	int		msg_ctlmni;

	atomic_t	msg_bytes;

	atomic_t	msg_hdrs;



	size_t		shm_ctlmax;

	size_t		shm_ctlall;

	int		shm_ctlmni;

	int		shm_tot;

};



extern struct ipc_namespace init_ipc_ns;



#ifdef CONFIG_SYSVIPC

#define INIT_IPC_NS(ns)		.ns		= &init_ipc_ns,

#else

#define INIT_IPC_NS(ns)

#endif



#if defined(CONFIG_SYSVIPC) && defined(CONFIG_IPC_NS)

extern void free_ipc_ns(struct kref *kref);

extern struct ipc_namespace *copy_ipcs(unsigned long flags,

						struct ipc_namespace *ns);



static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)

{

	if (ns)

		kref_get(&ns->kref);

	return ns;

}



static inline void put_ipc_ns(struct ipc_namespace *ns)

{

	kref_put(&ns->kref, free_ipc_ns);

}

#else

static inline struct ipc_namespace *copy_ipcs(unsigned long flags,

		struct ipc_namespace *ns)

{

	if (flags & CLONE_NEWIPC)

		return ERR_PTR(-EINVAL);



	return ns;

}



static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)

{

	return ns;

}



static inline void put_ipc_ns(struct ipc_namespace *ns)

{

}

#endif

#endif

init/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -436,6 +436,13 @@ config UTS_NS 
	  In this namespace tasks see different info provided with the

	  uname() system call



config IPC_NS

	bool "IPC namespace"

	depends on NAMESPACES && SYSVIPC

	help

	  In this namespace tasks work with IPC ids which correspond to

	  different IPC objects in different namespaces



config BLK_DEV_INITRD

	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"

	depends on BROKEN || !FRV

ipc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -7,4 +7,5 @@ obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o 
obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o

obj_mq-$(CONFIG_COMPAT) += compat_mq.o

obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)

obj-$(CONFIG_IPC_NS) += namespace.o

ipc/ipc_sysctl.c

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/nsproxy.h>

#include <linux/sysctl.h>

#include <linux/uaccess.h>

#include <linux/ipc_namespace.h>



static void *get_ipc(ctl_table *table)

{

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