nscommon: move to separate file

It's really awkward spilling the ns common infrastructure into multiple
headers. Move it to a separate file.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

include/linux/ns_common.h

@@ -31,6 +31,9 @@ struct ns_common {
 	};
 };
 
+int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,
+		   bool alloc_inum);
+
 #define to_ns_common(__ns)                              \
 	_Generic((__ns),                                \
 		struct cgroup_namespace *: &(__ns)->ns, \

include/linux/proc_ns.h

@@ -66,25 +66,6 @@ static inline void proc_free_inum(unsigned int inum) {}
 
 #endif /* CONFIG_PROC_FS */
 
-static inline int ns_common_init(struct ns_common *ns,
-				 const struct proc_ns_operations *ops,
-				 bool alloc_inum)
-{
-	if (alloc_inum) {
-		int ret;
-		ret = proc_alloc_inum(&ns->inum);
-		if (ret)
-			return ret;
-	}
-	refcount_set(&ns->count, 1);
-	ns->stashed = NULL;
-	ns->ops = ops;
-	ns->ns_id = 0;
-	RB_CLEAR_NODE(&ns->ns_tree_node);
-	INIT_LIST_HEAD(&ns->ns_list_node);
-	return 0;
-}
-
 #define ns_free_inum(ns) proc_free_inum((ns)->inum)
 
 #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)

kernel/Makefile

@@ -8,7 +8,7 @@ obj-y     = fork.o exec_domain.o panic.o \
 	    sysctl.o capability.o ptrace.o user.o \
 	    signal.o sys.o umh.o workqueue.o pid.o task_work.o \
 	    extable.o params.o \
-	    kthread.o sys_ni.o nsproxy.o nstree.o \
+	    kthread.o sys_ni.o nsproxy.o nstree.o nscommon.o \
 	    notifier.o ksysfs.o cred.o reboot.o \
 	    async.o range.o smpboot.o ucount.o regset.o ksyms_common.o
 

kernel/nscommon.c

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/ns_common.h>
+
+int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,
+		   bool alloc_inum)
+{
+	if (alloc_inum) {
+		int ret;
+		ret = proc_alloc_inum(&ns->inum);
+		if (ret)
+			return ret;
+	}
+	refcount_set(&ns->count, 1);
+	ns->stashed = NULL;
+	ns->ops = ops;
+	ns->ns_id = 0;
+	RB_CLEAR_NODE(&ns->ns_tree_node);
+	INIT_LIST_HEAD(&ns->ns_list_node);
+	return 0;
+}