if (ns == NULL)
return ERR_PTR(-ENOMEM);
+ atomic_inc(&nr_ipc_ns);
+
sem_init_ns(ns);
msg_init_ns(ns);
shm_init_ns(ns);
+ /*
+ * msgmni has already been computed for the new ipc ns.
+ * Thus, do the ipcns creation notification before registering that
+ * new ipcns in the chain.
+ */
+ ipcns_notify(IPCNS_CREATED);
+ register_ipcns_notifier(ns);
+
kref_init(&ns->kref);
return ns;
}
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;
ns = container_of(kref, struct ipc_namespace, kref);
+ /*
+ * Unregistering the hotplug notifier at the beginning guarantees
+ * that the ipc namespace won't be freed while we are inside the
+ * callback routine. Since the blocking_notifier_chain_XXX routines
+ * hold a rw lock on the notifier list, unregister_ipcns_notifier()
+ * won't take the rw lock before blocking_notifier_call_chain() has
+ * released the rd lock.
+ */
+ unregister_ipcns_notifier(ns);
sem_exit_ns(ns);
msg_exit_ns(ns);
shm_exit_ns(ns);
kfree(ns);
+ atomic_dec(&nr_ipc_ns);
+
+ /*
+ * Do the ipcns removal notification after decrementing nr_ipc_ns in
+ * order to have a correct value when recomputing msgmni.
+ */
+ ipcns_notify(IPCNS_REMOVED);
}