ipc: unify the syscalls code

This patch introduces a change into the sys_msgget(), sys_semget() and
sys_shmget() routines: they now share a common code, which is better for
maintainability.

Signed-off-by: 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, 17 insertions, 44 deletions

diff --git a/ipc/msg.c b/ipc/msg.c
index 08591a0278ce..c2ee26f01055 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -81,7 +81,7 @@ static struct ipc_ids init_msg_ids;
         ipc_buildid(&msg_ids(ns), id, seq)
 
 static void freeque(struct ipc_namespace *, struct msg_queue *);
-static int newque (struct ipc_namespace *ns, key_t key, int msgflg);
+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);
 #endif
@@ -144,10 +144,12 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
         ipc_rmid(&msg_ids(ns), &s->q_perm);
 }
 
-static int newque (struct ipc_namespace *ns, key_t key, int msgflg)
+static int newque(struct ipc_namespace *ns, struct ipc_params *params)
 {
         struct msg_queue *msq;
         int id, retval;
+        key_t key = params->key;
+        int msgflg = params->flg;
 
         msq = ipc_rcu_alloc(sizeof(*msq));
         if (!msq)
@@ -264,56 +266,27 @@ static void freeque(struct ipc_namespace *ns, struct msg_queue *msq)
         ipc_rcu_putref(msq);
 }
 
+static inline int msg_security(void *msq, int msgflg)
+{
+        return security_msg_queue_associate((struct msg_queue *) msq, msgflg);
+}
+
 asmlinkage long sys_msgget(key_t key, int msgflg)
 {
-        struct msg_queue *msq;
-        int ret;
         struct ipc_namespace *ns;
+        struct ipc_ops msg_ops;
+        struct ipc_params msg_params;
 
         ns = current->nsproxy->ipc_ns;
 
-        ret = idr_pre_get(&msg_ids(ns).ipcs_idr, GFP_KERNEL);
+        msg_ops.getnew = newque;
+        msg_ops.associate = msg_security;
+        msg_ops.more_checks = NULL;
 
-        if (key == IPC_PRIVATE)  {
-                if (!ret)
-                        ret = -ENOMEM;
-                else {
-                        mutex_lock(&msg_ids(ns).mutex);
-                        ret = newque(ns, key, msgflg);
-                        mutex_unlock(&msg_ids(ns).mutex);
-                }
-        } else {
-                mutex_lock(&msg_ids(ns).mutex);
-                msq = (struct msg_queue *) ipc_findkey(&msg_ids(ns), key);
-                if (msq == NULL) {
-                        /* key not used */
-                        if (!(msgflg & IPC_CREAT))
-                                ret = -ENOENT;
-                        else if (!ret)
-                                ret = -ENOMEM;
-                        else
-                                ret = newque(ns, key, msgflg);
-                } else {
-                        /* msq has been locked by ipc_findkey() */
-
-                        if (msgflg & IPC_CREAT && msgflg & IPC_EXCL)
-                                ret = -EEXIST;
-                        else {
-                                if (ipcperms(&msq->q_perm, msgflg))
-                                        ret = -EACCES;
-                                else {
-                                        ret = security_msg_queue_associate(
-                                                                msq, msgflg);
-                                        if (!ret)
-                                                ret = msq->q_perm.id;
-                                }
-                        }
-                        msg_unlock(msq);
-                }
-                mutex_unlock(&msg_ids(ns).mutex);
-        }
+        msg_params.key = key;
+        msg_params.flg = msgflg;
 
-        return ret;
+        return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
 }
 
 static inline unsigned long