Re: [PATCH 3/5] Move the IPC namespace under the option

[Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>]

Cedric Le Goater wrote:
> Pavel Emelyanov wrote:
>> Currently all the IPC namespace management code is in 
>> ipc/util.c. 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 knoweledge 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.
>>
>> Signied-off-by: Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
>       ^
> that sounds french :)

:)

> Also, for the code aesthetic, 
> 
> I think that ipc/ipc_namespace.c is a better name which fits
> the header file ipc/ipc_namespace.h.

Well, it already resides in ipc/ directory. I think it's a
mess to add one more ipc_ prefix.

> I'm wondering if it possible to move the init routines :
> 
> 	#ifdef CONFIG_NAMESPACES
> 	int {msg,sem,shm}_init_ns(struct ipc_namespace *ns)
> 	{
> 		...
> 	}
> 	#endif
> 
> from the ipc/{msg,sem,shm}.c file to the ipc/ipc_namespace.c file.
> It would look better in the code than using ugly #ifdef.

Hm... Looks like it is. I will remake the patches.

> Thanks !
> 
> C.
> 
>> ---
>>
>> diff --git a/include/linux/ipc.h b/include/linux/ipc.h
>> index 96988d1..b882610 100644
>> --- a/include/linux/ipc.h
>> +++ b/include/linux/ipc.h
>> @@ -100,56 +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;
>> -
>> -	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 */
>> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
>> new file mode 100644
>> index 0000000..3d8a516
>> --- /dev/null
>> +++ b/include/linux/ipc_namespace.h
>> @@ -0,0 +1,67 @@
>> +#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;
>> +
>> +	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_NAMESPACES)
>> +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
>> diff --git a/ipc/util.c b/ipc/util.c
>> index fd29246..44fb843 100644
>> --- a/ipc/util.c
>> +++ b/ipc/util.c
>> @@ -32,6 +32,7 @@
>>  #include <linux/proc_fs.h>
>>  #include <linux/audit.h>
>>  #include <linux/nsproxy.h>
>> +#include <linux/ipc_namespace.h>
>>
>>  #include <asm/unistd.h>
>>
>> @@ -50,66 +51,6 @@ struct ipc_namespace init_ipc_ns = {
>>  	},
>>  };
>>
>> -static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
>> -{
>> -	int err;
>> -	struct ipc_namespace *ns;
>> -
>> -	err = -ENOMEM;
>> -	ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
>> -	if (ns == NULL)
>> -		goto err_mem;
>> -
>> -	err = sem_init_ns(ns);
>> -	if (err)
>> -		goto err_sem;
>> -	err = msg_init_ns(ns);
>> -	if (err)
>> -		goto err_msg;
>> -	err = shm_init_ns(ns);
>> -	if (err)
>> -		goto err_shm;
>> -
>> -	kref_init(&ns->kref);
>> -	return ns;
>> -
>> -err_shm:
>> -	msg_exit_ns(ns);
>> -err_msg:
>> -	sem_exit_ns(ns);
>> -err_sem:
>> -	kfree(ns);
>> -err_mem:
>> -	return ERR_PTR(err);
>> -}
>> -
>> -struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
>> -{
>> -	struct ipc_namespace *new_ns;
>> -
>> -	BUG_ON(!ns);
>> -	get_ipc_ns(ns);
>> -
>> -	if (!(flags & CLONE_NEWIPC))
>> -		return ns;
>> -
>> -	new_ns = clone_ipc_ns(ns);
>> -
>> -	put_ipc_ns(ns);
>> -	return new_ns;
>> -}
>> -
>> -void free_ipc_ns(struct kref *kref)
>> -{
>> -	struct ipc_namespace *ns;
>> -
>> -	ns = container_of(kref, struct ipc_namespace, kref);
>> -	sem_exit_ns(ns);
>> -	msg_exit_ns(ns);
>> -	shm_exit_ns(ns);
>> -	kfree(ns);
>> -}
>> -
>>  /**
>>   *	ipc_init	-	initialise IPC subsystem
>>   *
>> diff --git a/ipc/namespace.c b/ipc/namespace.c
>> new file mode 100644
>> index 0000000..cef1139
>> --- /dev/null
>> +++ b/ipc/namespace.c
>> @@ -0,0 +1,73 @@
>> +/*
>> + * linux/ipc/namespace.c
>> + * Copyright (C) 2006 Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org> OpenVZ, SWsoft Inc.
>> + */
>> +
>> +#include <linux/ipc.h>
>> +#include <linux/msg.h>
>> +#include <linux/ipc_namespace.h>
>> +#include <linux/rcupdate.h>
>> +#include <linux/nsproxy.h>
>> +#include <linux/slab.h>
>> +
>> +#include "util.h"
>> +
>> +static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
>> +{
>> +	int err;
>> +	struct ipc_namespace *ns;
>> +
>> +	err = -ENOMEM;
>> +	ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
>> +	if (ns == NULL)
>> +		goto err_mem;
>> +
>> +	err = sem_init_ns(ns);
>> +	if (err)
>> +		goto err_sem;
>> +	err = msg_init_ns(ns);
>> +	if (err)
>> +		goto err_msg;
>> +	err = shm_init_ns(ns);
>> +	if (err)
>> +		goto err_shm;
>> +
>> +	kref_init(&ns->kref);
>> +	return ns;
>> +
>> +err_shm:
>> +	msg_exit_ns(ns);
>> +err_msg:
>> +	sem_exit_ns(ns);
>> +err_sem:
>> +	kfree(ns);
>> +err_mem:
>> +	return ERR_PTR(err);
>> +}
>> +
>> +struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
>> +{
>> +	struct ipc_namespace *new_ns;
>> +
>> +	BUG_ON(!ns);
>> +	get_ipc_ns(ns);
>> +
>> +	if (!(flags & CLONE_NEWIPC))
>> +		return ns;
>> +
>> +	new_ns = clone_ipc_ns(ns);
>> +
>> +	put_ipc_ns(ns);
>> +	return new_ns;
>> +}
>> +
>> +void free_ipc_ns(struct kref *kref)
>> +{
>> +	struct ipc_namespace *ns;
>> +
>> +	ns = container_of(kref, struct ipc_namespace, kref);
>> +	sem_exit_ns(ns);
>> +	msg_exit_ns(ns);
>> +	shm_exit_ns(ns);
>> +	kfree(ns);
>> +}
>> diff --git a/ipc/Makefile b/ipc/Makefile
>> index b93bba6..d81fb35 100644
>> --- a/ipc/Makefile
>> +++ b/ipc/Makefile
>> @@ -7,4 +7,5 @@ obj-$(CONFIG_SYSVIPC) += util.o msgutil.
>>  obj-$(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_NAMESPACES) += namespace.o
>>
>> diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
>> index 79e24e8..7f4235b 100644
>> --- a/ipc/ipc_sysctl.c
>> +++ b/ipc/ipc_sysctl.c
>> @@ -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)
>>  {
>> diff --git a/ipc/msg.c b/ipc/msg.c
>> index b7274db..eb74965 100644
>> --- a/ipc/msg.c
>> +++ b/ipc/msg.c
>> @@ -36,6 +36,7 @@
>>  #include <linux/seq_file.h>
>>  #include <linux/mutex.h>
>>  #include <linux/nsproxy.h>
>> +#include <linux/ipc_namespace.h>
>>
>>  #include <asm/current.h>
>>  #include <asm/uaccess.h>
>> @@ -92,6 +93,7 @@ static void __msg_init_ns(struct ipc_nam
>>  	ipc_init_ids(ids);
>>  }
>>
>> +#ifdef CONFIG_NAMESPACES
>>  int msg_init_ns(struct ipc_namespace *ns)
>>  {
>>  	struct ipc_ids *ids;
>> @@ -127,6 +129,7 @@ void msg_exit_ns(struct ipc_namespace *n
>>  	kfree(ns->ids[IPC_MSG_IDS]);
>>  	ns->ids[IPC_MSG_IDS] = NULL;
>>  }
>> +#endif
>>
>>  void __init msg_init(void)
>>  {
>> diff --git a/ipc/sem.c b/ipc/sem.c
>> index 45c7e57..2e9f449 100644
>> --- a/ipc/sem.c
>> +++ b/ipc/sem.c
>> @@ -82,6 +82,7 @@
>>  #include <linux/seq_file.h>
>>  #include <linux/mutex.h>
>>  #include <linux/nsproxy.h>
>> +#include <linux/ipc_namespace.h>
>>
>>  #include <asm/uaccess.h>
>>  #include "util.h"
>> @@ -130,6 +131,7 @@ static void __sem_init_ns(struct ipc_nam
>>  	ipc_init_ids(ids);
>>  }
>>
>> +#ifdef CONFIG_NAMESPACES
>>  int sem_init_ns(struct ipc_namespace *ns)
>>  {
>>  	struct ipc_ids *ids;
>> @@ -165,6 +167,7 @@ void sem_exit_ns(struct ipc_namespace *n
>>  	kfree(ns->ids[IPC_SEM_IDS]);
>>  	ns->ids[IPC_SEM_IDS] = NULL;
>>  }
>> +#endif
>>
>>  void __init sem_init (void)
>>  {
>> diff --git a/ipc/shm.c b/ipc/shm.c
>> index f28f2a3..2717cbc 100644
>> --- a/ipc/shm.c
>> +++ b/ipc/shm.c
>> @@ -38,6 +38,7 @@
>>  #include <linux/mutex.h>
>>  #include <linux/nsproxy.h>
>>  #include <linux/mount.h>
>> +#include <linux/ipc_namespace.h>
>>
>>  #include <asm/uaccess.h>
>>
>> @@ -97,6 +98,7 @@ static void do_shm_rmid(struct ipc_names
>>  		shm_destroy(ns, shp);
>>  }
>>
>> +#ifdef CONFIG_NAMESPACES
>>  int shm_init_ns(struct ipc_namespace *ns)
>>  {
>>  	struct ipc_ids *ids;
>> @@ -132,6 +134,7 @@ void shm_exit_ns(struct ipc_namespace *n
>>  	kfree(ns->ids[IPC_SHM_IDS]);
>>  	ns->ids[IPC_SHM_IDS] = NULL;
>>  }
>> +#endif
>>
>>  void __init shm_init (void)
>>  {
>> diff --git a/ipc/util.h b/ipc/util.h
>> index 99414a3..8972402 100644
>> --- a/ipc/util.h
>> +++ b/ipc/util.h
>> @@ -20,6 +20,8 @@ void sem_init (void);
>>  void msg_init (void);
>>  void shm_init (void);
>>
>> +struct ipc_namespace;
>> +
>>  int sem_init_ns(struct ipc_namespace *ns);
>>  int msg_init_ns(struct ipc_namespace *ns);
>>  int shm_init_ns(struct ipc_namespace *ns);
>> diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
>> index ee68964..5a27426 100644
>> --- a/kernel/nsproxy.c
>> +++ b/kernel/nsproxy.c
>> @@ -20,6 +20,7 @@
>>  #include <linux/mnt_namespace.h>
>>  #include <linux/utsname.h>
>>  #include <linux/pid_namespace.h>
>> +#include <linux/ipc_namespace.h>
>>
>>  static struct kmem_cache *nsproxy_cachep;
>>
>>
>>
> 
>