mnt: Factor out mntns nsid creation on restore

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/namespaces.h

@@ -50,6 +50,7 @@ extern int switch_ns(int pid, struct ns_desc *nd, int *rst);
 extern int restore_ns(int rst, struct ns_desc *nd);
 
 extern int dump_task_ns_ids(struct pstree_item *);
+extern struct ns_id *rst_new_ns_id(unsigned int id, pid_t pid, struct ns_desc *nd);
 extern int rst_add_ns_id(unsigned int id, pid_t pid, struct ns_desc *nd);
 extern struct ns_id *lookup_ns_by_id(unsigned int id, struct ns_desc *nd);
 

mount.c

@@ -1423,24 +1423,15 @@ static int rst_collect_local_mntns(void)
 {
 	struct ns_id *nsid;
 
-	nsid = shmalloc(sizeof(struct ns_id));
-	if (nsid == NULL)
+	nsid = rst_new_ns_id(0, getpid(), &mnt_ns_desc);
+	if (!nsid)
 		return -1;
 
-	nsid->nd = &mnt_ns_desc;
-	nsid->id = 0;
-	nsid->pid = getpid();
-	futex_set(&nsid->created, 1);
-
 	mntinfo = collect_mntinfo(nsid);
-	if (mntinfo == NULL)
+	if (!mntinfo)
 		return -1;
 
-	nsid->next = ns_ids;
-	ns_ids = nsid;
-
-	pr_info("Add namespace %d pid %d\n", nsid->id, nsid->pid);
-
+	futex_set(&nsid->created, 1);
 	return 0;
 }
 

namespaces.c

@@ -117,6 +117,24 @@ struct ns_id *ns_ids = NULL;
 static unsigned int ns_next_id = 1;
 unsigned long root_ns_mask = 0;
 
+struct ns_id *rst_new_ns_id(unsigned int id, pid_t pid, struct ns_desc *nd)
+{
+	struct ns_id *nsid;
+
+	nsid = shmalloc(sizeof(*nsid));
+	if (nsid) {
+		nsid->nd = nd;
+		nsid->id = id;
+		nsid->pid = pid;
+		futex_set(&nsid->created, 0);
+
+		nsid->next = ns_ids;
+		ns_ids = nsid;
+	}
+
+	return nsid;
+}
+
 int rst_add_ns_id(unsigned int id, pid_t pid, struct ns_desc *nd)
 {
 	struct ns_id *nsid;
@@ -129,20 +147,10 @@ int rst_add_ns_id(unsigned int id, pid_t pid, struct ns_desc *nd)
 		}
 	}
 
-	nsid = shmalloc(sizeof(struct ns_id));
-	if (nsid == NULL)
+	if (rst_new_ns_id(id, pid, nd) == NULL)
 		return -1;
 
-	nsid->nd = nd;
-	nsid->id = id;
-	nsid->pid = pid;
-	futex_set(&nsid->created, 0);
-
-	nsid->next = ns_ids;
-	ns_ids = nsid;
-
 	pr_info("Add namespace %d pid %d\n", nsid->id, nsid->pid);
-
 	return 0;
 }