[PATCH] Consolidate IPC namespace cleanup functions

[Pavel Emelyanov <xemul@openvz.org>]

When the IPC namespace is terminated all the IPC objects (i.e. ids)
living in it are freed. This is done in a similar way in X_exit_ns()
functions. All the code can be consolidated, saving 122 bytes when
the NAMESPACES are on.

This patch must be applied after the ones with the NAMESPACES config
option introduced.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---

 ipc/msg.c       |   23 ++++-------------------
 ipc/namespace.c |   39 +++++++++++++++++++++++++++++++++++++++
 ipc/sem.c       |   23 ++++-------------------
 ipc/shm.c       |   23 ++++-------------------
 ipc/util.h      |    6 +++---
 5 files changed, 54 insertions(+), 60 deletions(-)

diff --git a/ipc/namespace.c b/ipc/namespace.c
index cef1139..98de4e5 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -12,6 +12,45 @@
 
 #include "util.h"
 
+static void ipc_exit_ns(struct ipc_namespace *ns, struct ipc_ids *ids,
+		void (*free_fn)(struct ipc_namespace *ns, void *id))
+{
+	void *id;
+	int next_id;
+	int total, in_use;
+
+	mutex_lock(&ids->mutex);
+
+	in_use = ids->in_use;
+
+	for (total = 0, next_id = 0; total < in_use; next_id++) {
+		id = idr_find(&ids->ipcs_idr, next_id);
+		if (id == NULL)
+			continue;
+
+		free_fn(ns, id);
+		total++;
+	}
+	mutex_unlock(&ids->mutex);
+
+	kfree(ids);
+}
+
+static inline void sem_exit_ns(struct ipc_namespace *ns)
+{
+	ipc_exit_ns(ns, ns->ids[IPC_SEM_IDS], sem_free);
+}
+
+static inline void msg_exit_ns(struct ipc_namespace *ns)
+{
+	ipc_exit_ns(ns, ns->ids[IPC_MSG_IDS], msg_free);
+}
+
+static inline void shm_exit_ns(struct ipc_namespace *ns)
+{
+	ipc_exit_ns(ns, ns->ids[IPC_SHM_IDS], shm_free);
+}
+
 static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
 {
 	int err;
diff --git a/ipc/sem.c b/ipc/sem.c
index 2e9f449..8027a30 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -144,28 +144,13 @@ int sem_init_ns(struct ipc_namespace *ns
 	return 0;
 }
 
-void sem_exit_ns(struct ipc_namespace *ns)
+void sem_free(struct ipc_namespace *ns, void *id)
 {
 	struct sem_array *sma;
-	int next_id;
-	int total, in_use;
 
-	mutex_lock(&sem_ids(ns).mutex);
-
-	in_use = sem_ids(ns).in_use;
-
-	for (total = 0, next_id = 0; total < in_use; next_id++) {
-		sma = idr_find(&sem_ids(ns).ipcs_idr, next_id);
-		if (sma == NULL)
-			continue;
-		ipc_lock_by_ptr(&sma->sem_perm);
-		freeary(ns, sma);
-		total++;
-	}
-	mutex_unlock(&sem_ids(ns).mutex);
-
-	kfree(ns->ids[IPC_SEM_IDS]);
-	ns->ids[IPC_SEM_IDS] = NULL;
+	sma = (struct sem_array *)id;
+	ipc_lock_by_ptr(&sma->sem_perm);
+	freeary(ns, sma);
 }
 #endif
 
diff --git a/ipc/msg.c b/ipc/msg.c
index eb74965..9b8a155 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -106,28 +106,13 @@ int msg_init_ns(struct ipc_namespace *ns
 	return 0;
 }
 
-void msg_exit_ns(struct ipc_namespace *ns)
+void msg_free(struct ipc_namespace *ns, void *id)
 {
 	struct msg_queue *msq;
-	int next_id;
-	int total, in_use;
 
-	mutex_lock(&msg_ids(ns).mutex);
-
-	in_use = msg_ids(ns).in_use;
-
-	for (total = 0, next_id = 0; total < in_use; next_id++) {
-		msq = idr_find(&msg_ids(ns).ipcs_idr, next_id);
-		if (msq == NULL)
-			continue;
-		ipc_lock_by_ptr(&msq->q_perm);
-		freeque(ns, msq);
-		total++;
-	}
-	mutex_unlock(&msg_ids(ns).mutex);
-
-	kfree(ns->ids[IPC_MSG_IDS]);
-	ns->ids[IPC_MSG_IDS] = NULL;
+	msq = (struct msg_queue *)id;
+	ipc_lock_by_ptr(&msq->q_perm);
+	freeque(ns, msq);
 }
 #endif
 
diff --git a/ipc/shm.c b/ipc/shm.c
index 2717cbc..8f50166 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -111,28 +111,13 @@ int shm_init_ns(struct ipc_namespace *ns
 	return 0;
 }
 
-void shm_exit_ns(struct ipc_namespace *ns)
+void shm_free(struct ipc_namespace *ns, void *id)
 {
 	struct shmid_kernel *shp;
-	int next_id;
-	int total, in_use;
-
-	mutex_lock(&shm_ids(ns).mutex);
-
-	in_use = shm_ids(ns).in_use;
-
-	for (total = 0, next_id = 0; total < in_use; next_id++) {
-		shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
-		if (shp == NULL)
-			continue;
-		ipc_lock_by_ptr(&shp->shm_perm);
-		do_shm_rmid(ns, shp);
-		total++;
-	}
-	mutex_unlock(&shm_ids(ns).mutex);
 
-	kfree(ns->ids[IPC_SHM_IDS]);
-	ns->ids[IPC_SHM_IDS] = NULL;
+	shp = (struct shmid_kernel *)id;
+	ipc_lock_by_ptr(&shp->shm_perm);
+	do_shm_rmid(ns, shp);
 }
 #endif
 
diff --git a/ipc/util.h b/ipc/util.h
index 8972402..f1f0a31 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -26,9 +26,9 @@ 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_exit_ns(struct ipc_namespace *ns);
-void msg_exit_ns(struct ipc_namespace *ns);
-void shm_exit_ns(struct ipc_namespace *ns);
+void sem_free(struct ipc_namespace *ns, void *id);
+void msg_free(struct ipc_namespace *ns, void *id);
+void shm_free(struct ipc_namespace *ns, void *id);
 
 struct ipc_ids {
 	int in_use;