[PATCH 2.6.24-rc3-mm1 0/3] [resend] IPC: some code consolidation

[PATCH 2.6.24-rc3-mm1 0/3] [resend] IPC: some code consolidation

[pierre.peiffer]

Andrew,

	Following this discussion http://lkml.org/lkml/2007/11/27/54, I
resend the three patches that I've sent last friday to let you have all of
them in the right order.

Thanks,
-- 
Pierre Peiffer

[PATCH 2.6.24-rc3-mm1 1/3] IPC: make struct ipc_ids static in ipc_namespace

[pierre.peiffer]

[-- Attachment #1: ipc_make_idr_static_in_namespace.patch --]
[-- Type: text/plain, Size: 10481 bytes --]

From: Pierre Peiffer <pierre.peiffer@bull.net>

Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for
msg, sem and shm, structure used to store each ipcs)
These pointers are dynamically allocated for each icp_namespace as the
ipc_namespace itself (for the init namespace, they are initialized with
pointer to static variables instead)

It is so for historical reason: in fact, before the use of idr to store the
ipcs, the ipcs were stored in tables of variable length, depending of the
maximum number of ipcs allowed.
Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any
cases for each new ipc_namespace, there is no gain of memory in having them
allocated separately of the struct ipc_namespace.

This patch proposes to make this table static in the struct ipc_namespace.
Thus, we can allocate all in once and get rid of all the code needed to
allocate and free these ipc_ids separately.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
---
 include/linux/ipc_namespace.h |   13 +++++++++++--
 ipc/msg.c                     |   26 ++++----------------------
 ipc/namespace.c               |   25 ++++---------------------
 ipc/sem.c                     |   26 ++++----------------------
 ipc/shm.c                     |   26 ++++----------------------
 ipc/util.c                    |    6 +++---
 ipc/util.h                    |   16 ++++------------
 7 files changed, 34 insertions(+), 104 deletions(-)

Index: b/include/linux/ipc_namespace.h
===================================================================
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -2,11 +2,20 @@
 #define __IPC_NAMESPACE_H__
 
 #include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/rwsem.h>
+
+struct ipc_ids {
+	int in_use;
+	unsigned short seq;
+	unsigned short seq_max;
+	struct rw_semaphore rw_mutex;
+	struct idr ipcs_idr;
+};
 
-struct ipc_ids;
 struct ipc_namespace {
 	struct kref	kref;
-	struct ipc_ids	*ids[3];
+	struct ipc_ids	ids[3];
 
 	int		sem_ctls[4];
 	int		used_sems;
Index: b/ipc/msg.c
===================================================================
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -67,9 +67,7 @@ struct msg_sender {
 #define SEARCH_NOTEQUAL		3
 #define SEARCH_LESSEQUAL	4
 
-static struct ipc_ids init_msg_ids;
-
-#define msg_ids(ns)	(*((ns)->ids[IPC_MSG_IDS]))
+#define msg_ids(ns)	((ns)->ids[IPC_MSG_IDS])
 
 #define msg_unlock(msq)		ipc_unlock(&(msq)->q_perm)
 #define msg_buildid(id, seq)	ipc_buildid(id, seq)
@@ -80,30 +78,17 @@ static int newque(struct ipc_namespace *
 static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
 #endif
 
-static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void msg_init_ns(struct ipc_namespace *ns)
 {
-	ns->ids[IPC_MSG_IDS] = ids;
 	ns->msg_ctlmax = MSGMAX;
 	ns->msg_ctlmnb = MSGMNB;
 	ns->msg_ctlmni = MSGMNI;
 	atomic_set(&ns->msg_bytes, 0);
 	atomic_set(&ns->msg_hdrs, 0);
-	ipc_init_ids(ids);
+	ipc_init_ids(&msg_ids(ns));
 }
 
 #ifdef CONFIG_IPC_NS
-int msg_init_ns(struct ipc_namespace *ns)
-{
-	struct ipc_ids *ids;
-
-	ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
-	if (ids == NULL)
-		return -ENOMEM;
-
-	__msg_init_ns(ns, ids);
-	return 0;
-}
-
 void msg_exit_ns(struct ipc_namespace *ns)
 {
 	struct msg_queue *msq;
@@ -126,15 +111,12 @@ void msg_exit_ns(struct ipc_namespace *n
 	}
 
 	up_write(&msg_ids(ns).rw_mutex);
-
-	kfree(ns->ids[IPC_MSG_IDS]);
-	ns->ids[IPC_MSG_IDS] = NULL;
 }
 #endif
 
 void __init msg_init(void)
 {
-	__msg_init_ns(&init_ipc_ns, &init_msg_ids);
+	msg_init_ns(&init_ipc_ns);
 	ipc_init_proc_interface("sysvipc/msg",
 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
 				IPC_MSG_IDS, sysvipc_msg_proc_show);
Index: b/ipc/namespace.c
===================================================================
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -14,35 +14,18 @@
 
 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;
+		return ERR_PTR(-ENOMEM);
 
-	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;
+	sem_init_ns(ns);
+	msg_init_ns(ns);
+	shm_init_ns(ns);
 
 	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)
Index: b/ipc/sem.c
===================================================================
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -87,14 +87,12 @@
 #include <asm/uaccess.h>
 #include "util.h"
 
-#define sem_ids(ns)	(*((ns)->ids[IPC_SEM_IDS]))
+#define sem_ids(ns)	((ns)->ids[IPC_SEM_IDS])
 
 #define sem_unlock(sma)		ipc_unlock(&(sma)->sem_perm)
 #define sem_checkid(sma, semid)	ipc_checkid(&sma->sem_perm, semid)
 #define sem_buildid(id, seq)	ipc_buildid(id, seq)
 
-static struct ipc_ids init_sem_ids;
-
 static int newary(struct ipc_namespace *, struct ipc_params *);
 static void freeary(struct ipc_namespace *, struct sem_array *);
 #ifdef CONFIG_PROC_FS
@@ -118,30 +116,17 @@ static int sysvipc_sem_proc_show(struct 
 #define sc_semopm	sem_ctls[2]
 #define sc_semmni	sem_ctls[3]
 
-static void __sem_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void sem_init_ns(struct ipc_namespace *ns)
 {
-	ns->ids[IPC_SEM_IDS] = ids;
 	ns->sc_semmsl = SEMMSL;
 	ns->sc_semmns = SEMMNS;
 	ns->sc_semopm = SEMOPM;
 	ns->sc_semmni = SEMMNI;
 	ns->used_sems = 0;
-	ipc_init_ids(ids);
+	ipc_init_ids(&sem_ids(ns));
 }
 
 #ifdef CONFIG_IPC_NS
-int sem_init_ns(struct ipc_namespace *ns)
-{
-	struct ipc_ids *ids;
-
-	ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
-	if (ids == NULL)
-		return -ENOMEM;
-
-	__sem_init_ns(ns, ids);
-	return 0;
-}
-
 void sem_exit_ns(struct ipc_namespace *ns)
 {
 	struct sem_array *sma;
@@ -163,15 +148,12 @@ void sem_exit_ns(struct ipc_namespace *n
 		total++;
 	}
 	up_write(&sem_ids(ns).rw_mutex);
-
-	kfree(ns->ids[IPC_SEM_IDS]);
-	ns->ids[IPC_SEM_IDS] = NULL;
 }
 #endif
 
 void __init sem_init (void)
 {
-	__sem_init_ns(&init_ipc_ns, &init_sem_ids);
+	sem_init_ns(&init_ipc_ns);
 	ipc_init_proc_interface("sysvipc/sem",
 				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
 				IPC_SEM_IDS, sysvipc_sem_proc_show);
Index: b/ipc/util.c
===================================================================
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -782,7 +782,7 @@ static void *sysvipc_proc_next(struct se
 	if (ipc && ipc != SEQ_START_TOKEN)
 		ipc_unlock(ipc);
 
-	return sysvipc_find_ipc(iter->ns->ids[iface->ids], *pos, pos);
+	return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
 }
 
 /*
@@ -795,7 +795,7 @@ static void *sysvipc_proc_start(struct s
 	struct ipc_proc_iface *iface = iter->iface;
 	struct ipc_ids *ids;
 
-	ids = iter->ns->ids[iface->ids];
+	ids = &iter->ns->ids[iface->ids];
 
 	/*
 	 * Take the lock - this will be released by the corresponding
@@ -826,7 +826,7 @@ static void sysvipc_proc_stop(struct seq
 	if (ipc && ipc != SEQ_START_TOKEN)
 		ipc_unlock(ipc);
 
-	ids = iter->ns->ids[iface->ids];
+	ids = &iter->ns->ids[iface->ids];
 	/* Release the lock we took in start() */
 	up_read(&ids->rw_mutex);
 }
Index: b/ipc/util.h
===================================================================
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -10,7 +10,6 @@
 #ifndef _IPC_UTIL_H
 #define _IPC_UTIL_H
 
-#include <linux/idr.h>
 #include <linux/err.h>
 
 #define USHRT_MAX 0xffff
@@ -22,22 +21,14 @@ 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);
+void sem_init_ns(struct ipc_namespace *ns);
+void msg_init_ns(struct ipc_namespace *ns);
+void shm_init_ns(struct ipc_namespace *ns);
 
 void sem_exit_ns(struct ipc_namespace *ns);
 void msg_exit_ns(struct ipc_namespace *ns);
 void shm_exit_ns(struct ipc_namespace *ns);
 
-struct ipc_ids {
-	int in_use;
-	unsigned short seq;
-	unsigned short seq_max;
-	struct rw_semaphore rw_mutex;
-	struct idr ipcs_idr;
-};
-
 /*
  * Structure that holds the parameters needed by the ipc operations
  * (see after)
@@ -68,6 +59,7 @@ struct ipc_ops {
 };
 
 struct seq_file;
+struct ipc_ids;
 
 void ipc_init_ids(struct ipc_ids *);
 #ifdef CONFIG_PROC_FS
Index: b/ipc/shm.c
===================================================================
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -56,9 +56,7 @@ struct shm_file_data {
 static const struct file_operations shm_file_operations;
 static struct vm_operations_struct shm_vm_ops;
 
-static struct ipc_ids init_shm_ids;
-
-#define shm_ids(ns)	(*((ns)->ids[IPC_SHM_IDS]))
+#define shm_ids(ns)	((ns)->ids[IPC_SHM_IDS])
 
 #define shm_unlock(shp)			\
 	ipc_unlock(&(shp)->shm_perm)
@@ -72,14 +70,13 @@ static void shm_destroy (struct ipc_name
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
 
-static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
+void shm_init_ns(struct ipc_namespace *ns)
 {
-	ns->ids[IPC_SHM_IDS] = ids;
 	ns->shm_ctlmax = SHMMAX;
 	ns->shm_ctlall = SHMALL;
 	ns->shm_ctlmni = SHMMNI;
 	ns->shm_tot = 0;
-	ipc_init_ids(ids);
+	ipc_init_ids(&shm_ids(ns));
 }
 
 /*
@@ -98,18 +95,6 @@ static void do_shm_rmid(struct ipc_names
 }
 
 #ifdef CONFIG_IPC_NS
-int shm_init_ns(struct ipc_namespace *ns)
-{
-	struct ipc_ids *ids;
-
-	ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
-	if (ids == NULL)
-		return -ENOMEM;
-
-	__shm_init_ns(ns, ids);
-	return 0;
-}
-
 void shm_exit_ns(struct ipc_namespace *ns)
 {
 	struct shmid_kernel *shp;
@@ -131,15 +116,12 @@ void shm_exit_ns(struct ipc_namespace *n
 		total++;
 	}
 	up_write(&shm_ids(ns).rw_mutex);
-
-	kfree(ns->ids[IPC_SHM_IDS]);
-	ns->ids[IPC_SHM_IDS] = NULL;
 }
 #endif
 
 void __init shm_init (void)
 {
-	__shm_init_ns(&init_ipc_ns, &init_shm_ids);
+	shm_init_ns(&init_ipc_ns);
 	ipc_init_proc_interface("sysvipc/shm",
 				"       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime\n",
 				IPC_SHM_IDS, sysvipc_shm_proc_show);

-- 
Pierre Peiffer

[PATCH 2.6.24-rc3-mm1 2/3] IPC/semaphores: consolidate SEM_STAT and IPC_STAT commands

[pierre.peiffer]

[-- Attachment #1: ipc_sem_consolidate_stat_cmd.patch --]
[-- Type: text/plain, Size: 2898 bytes --]

From: Pierre Peiffer <pierre.peiffer@bull.net>

These both commands (SEM_STAT and IPC_STAT) are rather doing the same things
(only the meaning of the id given as input and the return value differ).
However, for the semaphores, they are handled in two different places
(two different functions).

This patch consolidates this for clarification by handling these both
commands in semctl_nolock(). It also removes one unused parameter for
this function.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
---

 ipc/sem.c |   38 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 22 deletions(-)

Index: b/ipc/sem.c
===================================================================
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -599,8 +599,8 @@ static unsigned long copy_semid_to_user(
 	}
 }
 
-static int semctl_nolock(struct ipc_namespace *ns, int semid, int semnum,
-		int cmd, int version, union semun arg)
+static int semctl_nolock(struct ipc_namespace *ns, int semid,
+			 int cmd, int version, union semun arg)
 {
 	int err = -EINVAL;
 	struct sem_array *sma;
@@ -639,14 +639,23 @@ static int semctl_nolock(struct ipc_name
 			return -EFAULT;
 		return (max_id < 0) ? 0: max_id;
 	}
+	case IPC_STAT:
 	case SEM_STAT:
 	{
 		struct semid64_ds tbuf;
 		int id;
 
-		sma = sem_lock(ns, semid);
-		if (IS_ERR(sma))
-			return PTR_ERR(sma);
+		if (cmd == SEM_STAT) {
+			sma = sem_lock(ns, semid);
+			if (IS_ERR(sma))
+				return PTR_ERR(sma);
+			id = sma->sem_perm.id;
+		} else {
+			sma = sem_lock_check(ns, semid);
+			if (IS_ERR(sma))
+				return PTR_ERR(sma);
+			id = 0;
+		}
 
 		err = -EACCES;
 		if (ipcperms (&sma->sem_perm, S_IRUGO))
@@ -656,8 +665,6 @@ static int semctl_nolock(struct ipc_name
 		if (err)
 			goto out_unlock;
 
-		id = sma->sem_perm.id;
-
 		memset(&tbuf, 0, sizeof(tbuf));
 
 		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
@@ -792,19 +799,6 @@ static int semctl_main(struct ipc_namesp
 		err = 0;
 		goto out_unlock;
 	}
-	case IPC_STAT:
-	{
-		struct semid64_ds tbuf;
-		memset(&tbuf,0,sizeof(tbuf));
-		kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
-		tbuf.sem_otime  = sma->sem_otime;
-		tbuf.sem_ctime  = sma->sem_ctime;
-		tbuf.sem_nsems  = sma->sem_nsems;
-		sem_unlock(sma);
-		if (copy_semid_to_user (arg.buf, &tbuf, version))
-			return -EFAULT;
-		return 0;
-	}
 	/* GETVAL, GETPID, GETNCTN, GETZCNT, SETVAL: fall-through */
 	}
 	err = -EINVAL;
@@ -971,15 +965,15 @@ asmlinkage long sys_semctl (int semid, i
 	switch(cmd) {
 	case IPC_INFO:
 	case SEM_INFO:
+	case IPC_STAT:
 	case SEM_STAT:
-		err = semctl_nolock(ns,semid,semnum,cmd,version,arg);
+		err = semctl_nolock(ns, semid, cmd, version, arg);
 		return err;
 	case GETALL:
 	case GETVAL:
 	case GETPID:
 	case GETNCNT:
 	case GETZCNT:
-	case IPC_STAT:
 	case SETVAL:
 	case SETALL:
 		err = semctl_main(ns,semid,semnum,cmd,version,arg);

-- 
Pierre Peiffer

[PATCH 2.6.24-rc3-mm1 3/3] IPC: consolidate sem_exit_ns(), msg_exit_ns and shm_exit_ns()

[pierre.peiffer]

[-- Attachment #1: ipc_consolidate_all_xxx_exit_ns.patch --]
[-- Type: text/plain, Size: 8043 bytes --]

sem_exit_ns(), msg_exit_ns() and shm_exit_ns() are all called when an ipc_namespace is
released to free all ipcs of each type.
But in fact, they do the same thing: they loop around all ipcs to free them
individually by calling a specific routine.

This patch proposes to consolidate this by introducing a common function, free_ipcs(),
that do the job. The specific routine to call on each individual ipcs is passed as
parameter. For this, these ipc-specific 'free' routines are reworked to take a
generic 'struct ipc_perm' as parameter.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
---
 include/linux/ipc_namespace.h |    5 ++++-
 ipc/msg.c                     |   28 +++++-----------------------
 ipc/namespace.c               |   30 ++++++++++++++++++++++++++++++
 ipc/sem.c                     |   27 +++++----------------------
 ipc/shm.c                     |   27 ++++++---------------------
 5 files changed, 50 insertions(+), 67 deletions(-)

Index: b/ipc/msg.c
===================================================================
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -72,7 +72,7 @@ struct msg_sender {
 #define msg_unlock(msq)		ipc_unlock(&(msq)->q_perm)
 #define msg_buildid(id, seq)	ipc_buildid(id, seq)
 
-static void freeque(struct ipc_namespace *, struct msg_queue *);
+static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);
 static int newque(struct ipc_namespace *, struct ipc_params *);
 #ifdef CONFIG_PROC_FS
 static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
@@ -91,26 +91,7 @@ void msg_init_ns(struct ipc_namespace *n
 #ifdef CONFIG_IPC_NS
 void msg_exit_ns(struct ipc_namespace *ns)
 {
-	struct msg_queue *msq;
-	struct kern_ipc_perm *perm;
-	int next_id;
-	int total, in_use;
-
-	down_write(&msg_ids(ns).rw_mutex);
-
-	in_use = msg_ids(ns).in_use;
-
-	for (total = 0, next_id = 0; total < in_use; next_id++) {
-		perm = idr_find(&msg_ids(ns).ipcs_idr, next_id);
-		if (perm == NULL)
-			continue;
-		ipc_lock_by_ptr(perm);
-		msq = container_of(perm, struct msg_queue, q_perm);
-		freeque(ns, msq);
-		total++;
-	}
-
-	up_write(&msg_ids(ns).rw_mutex);
+	free_ipcs(ns, &msg_ids(ns), freeque);
 }
 #endif
 
@@ -274,9 +255,10 @@ static void expunge_all(struct msg_queue
  * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held
  * before freeque() is called. msg_ids.rw_mutex remains locked on exit.
  */
-static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
+static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 {
 	struct list_head *tmp;
+	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
 
 	expunge_all(msq, -EIDRM);
 	ss_wakeup(&msq->q_senders, 1);
@@ -582,7 +564,7 @@ asmlinkage long sys_msgctl(int msqid, in
 		break;
 	}
 	case IPC_RMID:
-		freeque(ns, msq);
+		freeque(ns, &msq->q_perm);
 		break;
 	}
 	err = 0;
Index: b/ipc/namespace.c
===================================================================
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -44,6 +44,36 @@ struct ipc_namespace *copy_ipcs(unsigned
 	return new_ns;
 }
 
+/*
+ * free_ipcs - free all ipcs of one type
+ * @ns:   the namespace to remove the ipcs from
+ * @ids:  the table of ipcs to free
+ * @free: the function called to free each individual ipc
+ *
+ * Called for each kind of ipc when an ipc_namespace exits.
+ */
+void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
+	       void (*free)(struct ipc_namespace *, struct kern_ipc_perm *))
+{
+	struct kern_ipc_perm *perm;
+	int next_id;
+	int total, in_use;
+
+	down_write(&ids->rw_mutex);
+
+	in_use = ids->in_use;
+
+	for (total = 0, next_id = 0; total < in_use; next_id++) {
+		perm = idr_find(&ids->ipcs_idr, next_id);
+		if (perm == NULL)
+			continue;
+		ipc_lock_by_ptr(perm);
+		free(ns, perm);
+		total++;
+	}
+	up_write(&ids->rw_mutex);
+}
+
 void free_ipc_ns(struct kref *kref)
 {
 	struct ipc_namespace *ns;
Index: b/ipc/sem.c
===================================================================
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -94,7 +94,7 @@
 #define sem_buildid(id, seq)	ipc_buildid(id, seq)
 
 static int newary(struct ipc_namespace *, struct ipc_params *);
-static void freeary(struct ipc_namespace *, struct sem_array *);
+static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);
 #ifdef CONFIG_PROC_FS
 static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #endif
@@ -129,25 +129,7 @@ void sem_init_ns(struct ipc_namespace *n
 #ifdef CONFIG_IPC_NS
 void sem_exit_ns(struct ipc_namespace *ns)
 {
-	struct sem_array *sma;
-	struct kern_ipc_perm *perm;
-	int next_id;
-	int total, in_use;
-
-	down_write(&sem_ids(ns).rw_mutex);
-
-	in_use = sem_ids(ns).in_use;
-
-	for (total = 0, next_id = 0; total < in_use; next_id++) {
-		perm = idr_find(&sem_ids(ns).ipcs_idr, next_id);
-		if (perm == NULL)
-			continue;
-		ipc_lock_by_ptr(perm);
-		sma = container_of(perm, struct sem_array, sem_perm);
-		freeary(ns, sma);
-		total++;
-	}
-	up_write(&sem_ids(ns).rw_mutex);
+	free_ipcs(ns, &sem_ids(ns), freeary);
 }
 #endif
 
@@ -542,10 +524,11 @@ static int count_semzcnt (struct sem_arr
  * as a writer and the spinlock for this semaphore set hold. sem_ids.rw_mutex
  * remains locked on exit.
  */
-static void freeary(struct ipc_namespace *ns, struct sem_array *sma)
+static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 {
 	struct sem_undo *un;
 	struct sem_queue *q;
+	struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
 
 	/* Invalidate the existing undo structures for this semaphore set.
 	 * (They will be freed without any further action in exit_sem()
@@ -926,7 +909,7 @@ static int semctl_down(struct ipc_namesp
 
 	switch(cmd){
 	case IPC_RMID:
-		freeary(ns, sma);
+		freeary(ns, ipcp);
 		err = 0;
 		break;
 	case IPC_SET:
Index: b/ipc/shm.c
===================================================================
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -83,8 +83,11 @@ void shm_init_ns(struct ipc_namespace *n
  * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
  * Only shm_ids.rw_mutex remains locked on exit.
  */
-static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
+static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 {
+	struct shmid_kernel *shp;
+	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+
 	if (shp->shm_nattch){
 		shp->shm_perm.mode |= SHM_DEST;
 		/* Do not find it any more */
@@ -97,25 +100,7 @@ static void do_shm_rmid(struct ipc_names
 #ifdef CONFIG_IPC_NS
 void shm_exit_ns(struct ipc_namespace *ns)
 {
-	struct shmid_kernel *shp;
-	struct kern_ipc_perm *perm;
-	int next_id;
-	int total, in_use;
-
-	down_write(&shm_ids(ns).rw_mutex);
-
-	in_use = shm_ids(ns).in_use;
-
-	for (total = 0, next_id = 0; total < in_use; next_id++) {
-		perm = idr_find(&shm_ids(ns).ipcs_idr, next_id);
-		if (perm == NULL)
-			continue;
-		ipc_lock_by_ptr(perm);
-		shp = container_of(perm, struct shmid_kernel, shm_perm);
-		do_shm_rmid(ns, shp);
-		total++;
-	}
-	up_write(&shm_ids(ns).rw_mutex);
+	free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
 }
 #endif
 
@@ -832,7 +817,7 @@ asmlinkage long sys_shmctl (int shmid, i
 		if (err)
 			goto out_unlock_up;
 
-		do_shm_rmid(ns, shp);
+		do_shm_rmid(ns, &shp->shm_perm);
 		up_write(&shm_ids(ns).rw_mutex);
 		goto out;
 	}
Index: b/include/linux/ipc_namespace.h
===================================================================
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -43,7 +43,10 @@ extern struct ipc_namespace init_ipc_ns;
 #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);
+				       struct ipc_namespace *ns);
+extern void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
+		      void (*free)(struct ipc_namespace *,
+				   struct kern_ipc_perm *));
 
 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
 {

-- 
Pierre Peiffer