[CRIU] [PATCH v2 1/4] ns: Split __get_ns_id() in subfunction

[Kirill Tkhai]

Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 criu/include/namespaces.h |    1 +
 criu/namespaces.c         |   50 ++++++++++++++++++++++++++-------------------
 2 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/criu/include/namespaces.h b/criu/include/namespaces.h
index 4cd2c85..da81031 100644
--- a/criu/include/namespaces.h
+++ b/criu/include/namespaces.h
@@ -138,6 +138,7 @@ extern int prepare_namespace(struct pstree_item *item, unsigned long clone_flags
 extern int switch_ns(int pid, struct ns_desc *nd, int *rst);
 extern int restore_ns(int rst, struct ns_desc *nd);
 
+extern int read_ns_id(pid_t pid, struct ns_desc *nd, unsigned int *kid);
 extern int dump_task_ns_ids(struct pstree_item *);
 extern int predump_task_ns_ids(struct pstree_item *);
 extern struct ns_id *rst_new_ns_id(unsigned int id, pid_t pid, struct ns_desc *nd, enum ns_type t);
diff --git a/criu/namespaces.c b/criu/namespaces.c
index 04a1b11..3703349 100644
--- a/criu/namespaces.c
+++ b/criu/namespaces.c
@@ -386,6 +386,34 @@ int walk_namespaces(struct ns_desc *nd, int (*cb)(struct ns_id *, void *), void
 	return ret;
 }
 
+int read_ns_id(pid_t pid, struct ns_desc *nd, unsigned int *kid)
+{
+	int proc_dir, ret;
+	char ns_path[10], ns_id[32];
+
+	proc_dir = open_pid_proc(pid);
+	if (proc_dir < 0)
+		return -1;
+
+	sprintf(ns_path, "ns/%s", nd->str);
+	ret = readlinkat(proc_dir, ns_path, ns_id, sizeof(ns_id) - 1);
+	if (ret < 0) {
+		if (errno == ENOENT) {
+			/* The namespace is unsupported */
+			*kid = 0;
+			return 0;
+		}
+		pr_perror("Can't readlink ns link");
+		return -1;
+	}
+	ns_id[ret] = '\0';
+
+	*kid = parse_ns_link(ns_id, ret, nd);
+	BUG_ON(!*kid);
+
+	return 0;
+}
+
 static unsigned int generate_ns_id(int pid, unsigned int kid, struct ns_desc *nd,
 		struct ns_id **ns_ret)
 {
@@ -428,31 +456,11 @@ static unsigned int generate_ns_id(int pid, unsigned int kid, struct ns_desc *nd
 
 static unsigned int __get_ns_id(int pid, struct ns_desc *nd, protobuf_c_boolean *supported, struct ns_id **ns)
 {
-	int proc_dir, ret;
 	unsigned int kid;
-	char ns_path[10], ns_id[32];
 
-	proc_dir = open_pid_proc(pid);
-	if (proc_dir < 0)
-		return 0;
-
-	sprintf(ns_path, "ns/%s", nd->str);
-	ret = readlinkat(proc_dir, ns_path, ns_id, sizeof(ns_id) - 1);
-	if (ret < 0) {
-		if (errno == ENOENT) {
-			/* The namespace is unsupported */
-			kid = 0;
-			goto out;
-		}
-		pr_perror("Can't readlink ns link");
+	if (read_ns_id(pid, nd, &kid) < 0)
 		return 0;
-	}
-	ns_id[ret] = '\0';
 
-	kid = parse_ns_link(ns_id, ret, nd);
-	BUG_ON(!kid);
-
-out:
 	if (supported)
 		*supported = kid != 0;
 	return generate_ns_id(pid, kid, nd, ns);