IPC: consolidate sem_exit_ns(), msg_exit_ns() and shm_exit_ns()

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>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 22 deletions

diff --git a/ipc/sem.c b/ipc/sem.c
index 1f7e28d1d25d..0b45a4d383c6 100644
--- 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 *ns)
 #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_array * sma, ushort semnum)
  * 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_namespace *ns, int semid, int semnum,
 
         switch(cmd){
         case IPC_RMID:
-                freeary(ns, sma);
+                freeary(ns, ipcp);
                 err = 0;
                 break;
         case IPC_SET: