ns: Factor out namespace switching call

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

include/ipc_ns.h

 #ifndef __CR_IPC_NS_H__
 #define __CR_IPC_NS_H__
 
-extern int dump_ipc_ns(int ns_pid, int ns_id);
+extern int dump_ipc_ns(int ns_id);
 extern int prepare_ipc_ns(int pid);
 
 extern struct ns_desc ipc_ns_desc;

include/net.h

@@ -4,7 +4,7 @@
 #include "list.h"
 
 struct cr_imgset;
-extern int dump_net_ns(int pid, int ns_id);
+extern int dump_net_ns(int ns_id);
 extern int prepare_net_ns(int pid);
 extern int netns_pre_create(void);
 

include/uts_ns.h

 #ifndef __CR_UTS_NS_H__
 #define __CR_UTS_NS_H__
 
-extern int dump_uts_ns(int ns_pid, int ns_id);
+extern int dump_uts_ns(int ns_id);
 extern int prepare_utsns(int pid);
 
 extern struct ns_desc uts_ns_desc;

ipc_ns.c

@@ -456,7 +456,7 @@ static int dump_ipc_data(const struct cr_imgset *imgset)
 	return 0;
 }
 
-int dump_ipc_ns(int ns_pid, int ns_id)
+int dump_ipc_ns(int ns_id)
 {
 	int ret;
 	struct cr_imgset *imgset;
@@ -465,10 +465,6 @@ int dump_ipc_ns(int ns_pid, int ns_id)
 	if (imgset == NULL)
 		return -1;
 
-	ret = switch_ns(ns_pid, &ipc_ns_desc, NULL);
-	if (ret < 0)
-		goto err;
-
 	ret = dump_ipc_data(imgset);
 	if (ret < 0) {
 		pr_err("Failed to write IPC namespace data\n");

namespaces.c

@@ -424,27 +424,27 @@ int gen_predump_ns_mask(void)
 
 static int do_dump_namespaces(struct ns_id *ns)
 {
-	int ret = -1;
+	int ret;
+
+	ret = switch_ns(ns->pid, ns->nd, NULL);
+	if (ret)
+		return ret;
 
 	switch (ns->nd->cflag) {
-	case CLONE_NEWPID:
-	case CLONE_NEWNS:
-		ret = 0;
-		break;
 	case CLONE_NEWUTS:
 		pr_info("Dump UTS namespace %d via %d\n",
 				ns->id, ns->pid);
-		ret = dump_uts_ns(ns->pid, ns->id);
+		ret = dump_uts_ns(ns->id);
 		break;
 	case CLONE_NEWIPC:
 		pr_info("Dump IPC namespace %d via %d\n",
 				ns->id, ns->pid);
-		ret = dump_ipc_ns(ns->pid, ns->id);
+		ret = dump_ipc_ns(ns->id);
 		break;
 	case CLONE_NEWNET:
 		pr_info("Dump NET namespace info %d via %d\n",
 				ns->id, ns->pid);
-		ret = dump_net_ns(ns->pid, ns->id);
+		ret = dump_net_ns(ns->id);
 		break;
 	default:
 		pr_err("Unknown namespace flag %x", ns->nd->cflag);
@@ -485,6 +485,14 @@ int dump_namespaces(struct pstree_item *item, unsigned int ns_flags)
 		if (ns->pid == getpid())
 			continue;
 
+		switch (ns->nd->cflag) {
+			/* No data for pid namespaces to dump */
+			case CLONE_NEWPID:
+			/* Dumped explicitly with dump_mnt_namespaces() */
+			case CLONE_NEWNS:
+				continue;
+		}
+
 		pid = fork();
 		if (pid < 0) {
 			pr_perror("Can't fork ns dumper");

net.c

@@ -533,7 +533,7 @@ static int mount_ns_sysfs(void)
 	return ns_sysfs_fd >= 0 ? 0 : -1;
 }
 
-int dump_net_ns(int pid, int ns_id)
+int dump_net_ns(int ns_id)
 {
 	struct cr_imgset *fds;
 	int ret;
@@ -542,9 +542,7 @@ int dump_net_ns(int pid, int ns_id)
 	if (fds == NULL)
 		return -1;
 
-	ret = switch_ns(pid, &net_ns_desc, NULL);
-	if (!ret)
-		ret = mount_ns_sysfs();
+	ret = mount_ns_sysfs();
 	if (!ret)
 		ret = dump_links(fds);
 	if (!ret)

uts_ns.c

@@ -12,7 +12,7 @@
 #include "protobuf.h"
 #include "protobuf/utsns.pb-c.h"
 
-int dump_uts_ns(int ns_pid, int ns_id)
+int dump_uts_ns(int ns_id)
 {
 	int ret;
 	struct cr_img *img;
@@ -23,10 +23,6 @@ int dump_uts_ns(int ns_pid, int ns_id)
 	if (!img)
 		return -1;
 
-	ret = switch_ns(ns_pid, &uts_ns_desc, NULL);
-	if (ret < 0)
-		goto err;
-
 	ret = uname(&ubuf);
 	if (ret < 0) {
 		pr_perror("Error calling uname");